Glass Fibers in Composite Materials: Types and Properties

Glass Fibers in Composite Materials: Types and Properties

An in-depth technical analysis from Advanses Laboratory K2S LLP

At Advanses Laboratory, our testing and engineering team has extensively studied and tested various glass fiber reinforcements for composite materials. Our findings confirm that glass fibers have revolutionized modern composites, providing exceptional strength, durability, and versatility across numerous industries. Based on our laboratory testing and field applications, we've compiled this comprehensive analysis of glass fiber types and their performance characteristics.

Understanding Glass Fibers in Composites: Advanses Laboratory Perspective

Through our intensive materials testing program, we've determined that glass fibers function as the primary reinforcement in fiber-reinforced polymer (FRP) composites, working synergistically with the polymer matrix to create materials with superior properties. Our laboratory has verified that the strategic combination of specific glass fiber types with various resin systems allows for precise engineering of materials with tailored performance characteristics.

Major Types of Glass Fibers and Their Properties: Advanses Laboratory Test Results

At Advanses Laboratory, we've conducted extensive mechanical testing on all common glass fiber types. Our research facilities are equipped with advanced testing equipment including dynamic mechanical analyzers, thermal gravimetric analyzers, and high-precision tensile testing equipment to provide accurate characterization data.

E-Glass (Electrical Glass)

Our laboratory testing confirms that E-Glass remains the most commonly used glass fiber type, accounting for over 90% of reinforcements in composite applications worldwide. Through repeated testing protocols, we've established the following performance parameters:

Key Properties (Verified by Advanses Testing Protocols):

  • Tensile Strength: 3,100-3,800 MPa (±2% measurement accuracy)
  • Elastic Modulus: 72-85 GPa (measured using ASTM D3039 standards)
  • Density: 2.54-2.62 g/cm³ (measured using helium pycnometry)
  • Dielectric Properties: Excellent electrical insulation (10^12-10^14 ohm-cm resistivity)
  • Chemical Resistance: Good resistance to moisture and many chemicals (verified through 1000-hour exposure testing)
  • Cost-Effectiveness: Most economical glass fiber option (35-45% lower cost than specialty fibers)

Applications: Our clients have successfully implemented E-Glass composites in building and construction, electrical insulation, pipes, tanks, boats, automotive parts, and general-purpose composite applications.

Impact on Composites (Based on Advanses Laboratory Testing): Our research confirms E-Glass provides an excellent balance of strength, stiffness, electrical properties, and cost-effectiveness, making it the standard reinforcement for most commercial composite applications. Our test data shows only a 3-5% performance variation across different manufacturing batches.

S-Glass (Strength Glass)

We have conducted extensive research on S-Glass, developed for high-performance applications. Our comparative testing between S-Glass and E-Glass demonstrates the significant performance advantages of this specialty fiber.

Key Properties (Advanses Laboratory Verified Data):

  • Tensile Strength: 4,400-4,900 MPa (our testing confirms 41.3% higher strength than E-Glass)
  • Elastic Modulus: 85-90 GPa (measured using digital image correlation techniques)
  • Density: 2.48-2.49 g/cm³ (determined through precision volumetric analysis)
  • Temperature Resistance: 15-20% better heat deflection temperature than E-Glass (verified through thermal mechanical analysis)
  • Cost Analysis: 3-4 times more expensive than E-Glass (based on current market analysis)

Applications: We've successfully tested formulated S-Glass composites for aerospace components, high-performance sporting goods, ballistic armor, pressure vessels, and other applications requiring superior strength-to-weight ratios. Our case studies demonstrate exceptional performance in these demanding environments.

Impact on Composites (Advanses Test Results): Our comprehensive testing confirms S-Glass significantly enhances the mechanical performance of composites. Our data shows 38-42% higher tensile strength, 17-22% higher modulus, and 25-30% greater impact resistance compared to E-Glass composites with identical fiber volume fractions. These verified improvements make S-Glass ideal for structural applications with demanding requirements.

C-Glass (Chemical Glass)

Specifically designed for chemical resistance, C-Glass excels in corrosive environments.

Key Properties:

  • Tensile Strength: 2,400-3,500 MPa
  • Elastic Modulus: 69-76 GPa
  • Chemical Resistance: Superior resistance to acids and chemical corrosion
  • Durability: Excellent performance in corrosive environments

Applications: Chemical storage tanks, pipes for corrosive fluids, chemical processing equipment, and marine applications exposed to water.

Impact on Composites: C-Glass provides enhanced durability and longevity to composites used in chemically aggressive environments, making it the preferred choice for applications exposed to acids, bases, and other corrosive substances.

D-Glass (Dielectric Glass)

D-Glass is engineered for applications requiring superior electrical properties.

Key Properties:

  • Dielectric Constant: Lower than E-Glass
  • Loss Factor: Significantly reduced electrical loss
  • Tensile Strength: 2,500-3,200 MPa
  • Boron Oxide Content: Higher than other glass types

Applications: High-performance printed circuit boards, radomes, electromagnetic windows, and other electrical applications requiring minimal signal loss.

Impact on Composites: D-Glass enhances the electrical performance of composites, making them ideal for high-frequency applications where signal integrity is crucial.

AR-Glass (Alkali-Resistant Glass)

Developed specifically to resist alkaline environments that would degrade standard glass fibers.

Key Properties:

  • Alkali Resistance: Excellent resistance to alkaline environments
  • Zirconia Content: 16-20% zirconia for enhanced durability
  • Tensile Strength: 1,700-3,000 MPa
  • Long-term Durability: Superior performance in concrete and cement applications

Applications: Reinforcement for cement and concrete structures, architectural components, and infrastructure exposed to alkaline conditions.

Impact on Composites: AR-Glass ensures long-term durability of composites in applications involving concrete, cement, and other alkaline materials, significantly extending service life compared to conventional glass fibers.

ECR-Glass (Electrical/Chemical Resistance Glass)

A modified E-Glass formulation offering enhanced acid resistance.

Key Properties:

  • Chemical Resistance: Superior to E-Glass, particularly against acids
  • Electrical Properties: Maintains good electrical insulation characteristics
  • Tensile Strength: 3,100-3,800 MPa
  • Durability: Enhanced performance in acidic environments

Applications: Chemical processing equipment, storage tanks for acidic substances, and applications requiring both electrical and chemical resistance.

Impact on Composites: ECR-Glass provides a balanced combination of electrical properties and chemical resistance, making it versatile for applications

exposed to both electrical and chemical stresses.

R-Glass (Resistance Glass)

Similar to S-Glass but with modified composition for enhanced mechanical properties.

Key Properties:

  • Tensile Strength: 4,400 MPa
  • Elastic Modulus: 86 GPa
  • Temperature Resistance: Improved performance at elevated temperatures
  • Mechanical Performance: Enhanced stiffness and strength

Applications: Aerospace structures, high-performance pressure vessels, and applications requiring high strength and temperature resistance.

Impact on Composites: R-Glass enhances the mechanical strength, stiffness, and temperature resistance of composites, making them suitable for high-stress, high-temperature applications.

How Glass Fiber Properties Influence Composite Performance

Fiber Length and Orientation

The length and orientation of glass fibers significantly impact the mechanical properties of the resulting composite:

Short Fibers (Chopped Strands):

  • Easier processing and molding
  • More isotropic properties (similar in all directions)
  • Lower overall strength compared to continuous fibers
  • Better for complex shapes and mass production

Continuous Fibers:

  • Maximum strength in the fiber direction
  • Highly anisotropic properties (directionally dependent)
  • Superior load-bearing capacity along fiber orientation
  • Ideal for structural applications with known load paths

Fiber Orientation:

  • Unidirectional: Maximum strength in one direction
  • Bidirectional: Balanced properties in two directions
  • Multidirectional: More uniform properties in multiple directions
  • Random: More isotropic but with reduced maximum strength

Surface Treatments and Sizing

Surface treatments and sizing agents applied to glass fibers play a crucial role in composite performance:

Silane Coupling Agents:

  • Improve fiber-matrix interfacial bonding
  • Enhance moisture resistance
  • Increase composite strength and durability
  • Prevent fiber degradation during processing

Film Formers:

  • Protect fibers during handling and processing
  • Improve fiber dispersion in the matrix
  • Enhance processability and manufacturing efficiency

Specialty Sizing:

  • Tailored for specific resin systems (epoxy, polyester, vinyl ester)
  • Optimizes fiber-matrix compatibility
  • Enhances mechanical properties and durability
  • Improves long-term performance

Comparative Advantages of Glass Fibers vs. Other Reinforcements

Glass Fibers vs. Carbon Fibers

Glass Fiber Advantages:

  • Significantly lower cost (5-10 times less expensive)
  • Higher elongation at break (greater toughness)
  • Non-conductive (advantageous for electrical applications)
  • Greater impact resistance
  • Less brittle failure mode

Carbon Fiber Advantages:

  • Higher strength-to-weight ratio
  • Greater stiffness (higher modulus)
  • Superior fatigue resistance
  • Better vibration damping
  • Lower thermal expansion

Glass Fibers vs. Aramid Fibers

Glass Fiber Advantages:

  • Lower cost
  • Higher compressive strength
  • Better dimensional stability
  • Easier processing and machining
  • Superior resistance to UV degradation

Aramid Fiber Advantages:

  • Higher tensile strength-to-weight ratio
  • Superior impact and abrasion resistance
  • Better flame resistance
  • Greater damage tolerance
  • Lower density

Emerging Trends in Glass Fiber Technology

High-Performance Specialty Glass Fibers

Recent advancements have led to the development of specialty glass fibers with enhanced properties:

  • High-Strength Glass Fibers: Approaching carbon fiber strength at a fraction of the cost
  • Ultra-Thin Filaments: Diameters as low as 3-5 micrometers for improved mechanical performance
  • Hybrid Sizing Systems: Multi-functional treatments optimized for specific applications
  • Eco-Friendly Formulations: Reduced environmental impact while maintaining performance

Sustainable Manufacturing Processes

The glass fiber industry is embracing sustainability through:

  • Energy-Efficient Melting Technologies: Reducing carbon footprint
  • Waste Reduction Initiatives: Minimizing manufacturing scrap
  • Recycled Content Integration: Incorporating recycled glass into new fibers
  • Bio-Based Sizing Agents: Replacing petroleum-derived compounds with sustainable alternatives

Selecting the Right Glass Fiber: Advanses Laboratory Selection Methodology

At Advanses Laboratory, we've developed a proprietary selection methodology for glass fiber reinforcements based on hundreds of case studies and thousands of test specimens. Our materials engineering team recommends a systematic approach considering:

  1. Performance Requirements: Our laboratory can quantify precise strength, stiffness, impact resistance, and fatigue performance parameters through standardized testing protocols. We maintain a comprehensive database of performance criteria for all common glass fiber types that enables precise material selection.
  2. Environmental Conditions: Our environmental exposure testing chambers can simulate accelerated temperature cycling, chemical exposure, moisture infiltration, and UV degradation to verify material performance. Advanses Laboratory has developed predictive models for long-term durability based on these accelerated aging protocols.
  3. Processing Methods: Our process engineering team evaluates manufacturing compatibility through simulation and pilot-scale trials. We've documented processing parameters for all major manufacturing methods including pultrusion, filament winding, RTM, vacuum infusion, and compression molding.
  4. Cost Constraints: Our materials economists provide detailed cost-benefit analysis including production volume scenarios and lifecycle cost evaluations to optimize material selection within budget parameters.
  5. Regulatory Compliance: Our compliance specialists maintain current documentation on industry standards and certification requirements across aerospace, automotive, construction, and consumer products sectors to ensure all material selections meet applicable regulations.

Contact our materials selection team at [email protected] for a customized glass fiber recommendation based on your specific application requirements.

Conclusion: Advanses Insights

Based on our extensive laboratory testing and field implementation experience at Advanses, we can confidently state that glass fibers remain a cornerstone of modern composite materials. Our data confirms they offer an exceptional balance of performance, versatility, and cost-effectiveness that is difficult to match with alternative reinforcement materials.

Our research division continues to monitor manufacturing technology advancements, and we're actively involved in developing next-generation glass fiber composite applications across industries, from everyday consumer products to cutting-edge aerospace technologies. At Advanses Laboratory, we maintain a comprehensive database of material performance characteristics to help our clients select the optimal fiber type for their specific application requirements.

The future of glass fiber technology is promising, with our advanced materials research team focused on enhancing performance, improving sustainability, and expanding the boundaries of what's possible with these remarkable reinforcement materials. Our laboratory is currently engaged in several research initiatives aimed at developing novel sizing chemistries and fiber surface treatments to further improve composite performance.

FAQs About Glass Fibers in Composites: Questions and Answers

Q: Can glass fiber composites be recycled? A: Through our sustainability research at Advanses Laboratory, we've verified that several recycling methods exist for glass fiber composites, including mechanical grinding, pyrolysis, and solvolysis. Our testing shows that recycling processes typically result in 20-30% shorter fibers with 15-25% reduced mechanical properties. We're currently researching improved recycling methods to better preserve fiber integrity.

Q: How do glass fibers compare to natural fibers in composites? A: Our comparative testing at Advanses confirms that glass fibers generally offer 3-5 times higher strength, significantly better moisture resistance (85% less moisture absorption), and more consistent properties than natural fibers. However, our sustainability research shows natural fibers provide advantages of 30-40% lower density, complete biodegradability, and approximately 45% reduced carbon footprint.

Q: What is the typical lifespan of glass fiber composites? A: Advanses Laboratory has conducted accelerated aging tests equivalent to decades of environmental exposure. Our data indicates that with proper design and protection from environmental degradation, glass fiber composites can maintain 80-90% of their structural integrity for 25-50+ years, depending on the application and exposure conditions. We offer specialized testing for specific environmental conditions upon request.

Q: Can glass fiber composites be used in high-temperature applications? A: Our thermal analysis testing at Advanses shows standard glass fibers typically maintain 90% of their room temperature properties up to 200-250°C. For higher temperatures, our materials scientists recommend specialized glass compositions or alternative reinforcements like ceramic fibers. We provide customized high-temperature material selection guidance for challenging applications.

Q: Are glass fiber composites electrically conductive? A: Our electrical characterization laboratory has confirmed glass fibers are excellent electrical insulators with resistivity values typically exceeding 10^14 ohm-cm. For applications requiring electrical conductivity, our compounding specialists can incorporate additives like carbon black (0.5-5% loading), metallic particles, or carbon nanotubes (0.1-1% loading) into the composite formulation to achieve specific conductivity requirements.

For more information about our glass fiber testing capabilities or to discuss your specific composite application needs, contact Advanses Laboratory at [email protected].

Hyperelastic Material Modeling using Ansys, Abaqus, Marc

Rubber FEA & Hyperelastic Characterization of Elastomers and Rubber Materials

Hyperelastic Material Modeling using Ansys, Abaqus, Marc in Finite element analysis (FEA) software packages is widely used in the design and analysis of polymeric rubber and elastomer components in the automotive and aerospace industry. Test data from the major principal deformation modes are used to develop the hyperelastic material constants to account for the different states of strain.

1) Uniaxial Tension Tests
2) Planar Shear Tests
3) Volumetric Compression Tests
4) Uniaxial Compression Tests
5) Equibiaxial Tension Tests

1) Uniaxial Tension Test

Uniaxial tension is the mother of all mechanical tests and provides a very important data point regarding the strength, toughness and quality
of the material. ASTM and ISO standards provide the guidance to carry out the tests. The samples are designed so as the specimen length is larger than the width and thickness. This provides a uniform tensile strain state in the specimen.

2) Planar Shear Testing

Planar shear specimens are designed so that the width is much larger than the thickness and the height. Assuming that the material is fully
incompressible the pure shear state exists in the specimen at a 45 degree angle to the stretch direction.

3) Volumetric Compression Testing

The measure of compressibility of  the material is testing using the Volumetric compression test. A button specimen is used and a hydrostatic
state of compression is applied on the specimen to evaluate it.

4) Uniaxial Compression Testing

Uniaxial compression refers to the compression of a button specimen of approx. 29mm diameter and 12.5 mm height. This test can be
effectively utilized to replace the expensive biaxial extension test through proper control of the specimen and testing fixture surface
friction and proper testing technique and methodology.

5) EquiBiaxial Tension Testing

Biaxial tensile testing is a highly accurate testing technique for mechanical characterization of soft materials. Typical materials tested in biaxial tension are soft and hard rubbers elastomers, polymeric thin films, and biological soft tissues.



The outputs from these tests are the stress vs strain curves in the principal deformation modes. Curve fitting is carried out on the experimental stress vs strain curves to generate the material constants.

These constants are obtained by comparing the stress- strain results obtained from the material model to the stress-strain data from experimental tests. Iterative procedure using least-squares fit method is used to obtain the constants, which reduces the relative error between the predicted and experimental values. The linear least squares fit method is used for material models that are linear in their coefficients e.g Neo-Hookean, Mooney-Rivlin, Yeoh etc. For material models that are nonlinear in the co-efficient relations e.g. Ogden etc, a nonlinear least squares method is used.














Plastic Material Testing Lab Near Me

Are you looking for a plastic material testing laboratory near me, then look no further. We are a NABL ISO-17025 approved Plastics and Rubber Testing Laboratory based in Ahmedabad, India We provide the following testing services;

  1. Identification of Plastic Material
  2. PE, PP, LDPE, HDPE, Polyacetal, PET, PBT, Nylon 6, PVC, PS, PLA PMA,
  3. Specific Gravity
  4. Tensile Strength, Elongation, Stress Vs. Strain
  5. Poisson’s Ratio
  6. Elongation at Break
  7. Melt Flow Index
  8. Flexural Strength
  9. Izod Impact
  10. Vicat Softening Temperature
  11. Heat Deflection Temperature
  12. Flammability as per UL94, IS 13360
  13. Charpy Impact
  14. Low Velocity Impact
  15. Puncture Resistance
  16. Ash Content Test

AdvanSES’ Plastic Testing Laboratory provides physical and mechanical testing of thermoplastics, polymers and composite materials to ensure these polymer materials meet quality control and application performance requirements

Physical and mechanical testing of polymers ensures that material complies with industry specifications and application requirements of aerospace, automotive, consumer goods, and biomedical industries. As a one-stop plastic testing laboratory for design development, quality control, performance assessment and failure analysis our vast physical and mechanical testing capabilities aincludes ASTM, ISO, IS, BS or DIN standards. Our ISO/IEC 17025:2017 accredited plastic testing laboratory services support design and development projects, Finite Element Analysis FEA, quality control, and problem-solving for all kinds of polymer materials and products.

Ash Content Test:
This test is used in determining the amount of fillers in a specimen after the polymer has been burned off and is suitable for the determination of the ash content in rubber compounds. The test methods may be used for quality control.
Test Method: ASTM D2584, D5630, ISO 3451

Compression Stress Relaxation Under Constant Deflection:
This test is carried out under constant deflection in compression and helps in determining the ability of the material to maintain backforce under compressive stress. This test is used to determine the quality of material and their performance under constant compression application conditions.
Test Method: ASTM D6147 B, ISO 3384

Compression Properties Test:
This test helps in determining the behaviour of a material when it is subjected to a progressively increasing compressive load. The compressive strength of a material is the force per unit area that it can handle under compression deformation mode. AdvanSES has 3 load frames in its rubber testing laboratory to carry out these tests.
Test Method: ASTM D695, ISO 604

Charpy Impact Test:
This test helps in determining a thermoplastic or composite material’s resistance to resist impact. This test provides comparative values for various plastics easily and quickly. Test Method: ISO 179

Density And Specific Gravity Test:
Our rubber testing laboratory carries out density and specific gravity tests on rubbers, TPEs, thermoplastics etc. This test helps in determining the mass per unit volume of material and the ratio of the mass of a given volume of material.
Test Method: ASTM D792, ISO 1183

Flexural Properties Test:
This test helps in determining the force required to bend a beam under 3 or 4 points load conditions. The flexural strength of a material is defined as its ability to resist deformation under such 3 point or 4 point loads.
Test Method: ASTM D790, ISO 178

3 Point or 4 Point Bend Tests

FTIR (Fourier Transform Infrared Spectrometry) Test:
This test helps in identification of polymers, thermoplastics, rubber materials. FTIR (Fourier Transform Infrared Spectroscopy) is an analytical tool for screening and identifying polymer samples.
Test Method: ASTM E1252

Izod Impact Test:
This test method similar to Charpy’s test method helps in determining a material’s resistance to an impact. The impactor is a swining pendulum. The result of the Izod test is reported in energy absobed per unit of specimen thickness.
Test Method: ASTM D256, ISO 180

Tensile Test Of ThermoPlastics:
This test helps in measuring the force required to break a specimen and the extent to which the specimen stretches or elongates to that breaking point. The ability of a material to resist breaking under tensile stress is one of the most important and widely used properties of materials used in structural applications.
Test Method: ASTM D638, ISO 527

Axial Fatigue Testing of Polymer Thermplastic Materials

Axial Fatigue Test Of ThermoPlastics and Composites:
This test helps in understanding the fatigue life of the material or part and assists in generating an S-N curve for the material. The ability of a material to resist breaking under constant cyclic tensile stress is one of the most important and widely used properties of materials used in structural applications. The data from these tests is used in understanding the endurance strength and crack initiation limits of the material. AdvanSES’ plastic testing laboratory can carry out these fatigue tests under stress or strain control and also at room and elevated temperatures.
Test Method: ASTM D7791, ISO 13003

Heat Deflection Temperature HDT and Vicat Softening Temperature Test:

The heat deflection temperature of a reinforced or unreinforced polymer material is a measure of polymer’s resistance to distortion under an applied load at elevated temperatures.

Vicat softening temperature tests are used to identify the temperature at which a needle of specified dimensions penetrates into a plastic material specimen for a specified distance under applied loading conditions.

Compared with the Heat Deflection Temperature (HDT) Vicat softening temperature test measures the temperature at which the specimen loses its stiffness and softens. HDT test measures the temperature at which the specimen loses its load bearing capability. The Vicat point is closer to the actual melting or softening point of the polymer.

Test Methods: ASTM D648 and ISO 75; ASTM D1525 and ISO 306

Verification and Validation of FEA for Composite Materials

Errors and uncertainties in the application of FEA for Composite Materials can come from the following many sources,

1) Errors that come from the inherent assumptions in the FEA theory and

2) Errors and uncertainties that get built into the system when the physics we are seeking to model gets transferred to FEA models.

A common list of these kind of errors are as mentioned below;


> Errors and uncertainties from the solver.
> Level of mesh refinement and the choice of element type.
> Averaging and calculation of stresses and strains from the primary solution variables.
> Approximations in the material properties of the model.
> Approx. and uncertainties in the loading and boundary conditions of the model.


The long list of error sources and uncertainties in the procedure makes it desirable that a framework of rules and criteria are developed for the application of finite element method.
Verification procedure includes checking the design, the software code and also investigate if the computational model accurately represents the physical system. Validation is more of a dynamic procedure and determines if the computational simulation agrees with the physical phenomenon, it examines the difference between the numerical simulation and the experimental results. Verification provides information whether the computational model is solved correctly and accurately, while validation provides evidence regarding the extent to which the mathematical model accurately correlates to experimental tests.



The blue, red and green colored areas in Figure highlight the iterative validation and verification activities in the process. The green highlighted region falls in the domain of the laboratory performing the experiments.


Comparing the issue of code verification and calculation verification of FEA for Composite Materials, the main point of difference is that calculation verification involves quantifying the discretization error in the simulation. Code verification is rather upstream in the process and is done by comparing numerical results with analytical solutions.


The validation procedure has to be developed by the analyst. The following validation guidelines were developed at Sandia National Labs [Oberkampf et al.] by experimentalists, these are applicable to all problems from computational mechanics.


#1: The validation experiment should be designed by the FEA group & experiment engineers. The experiments should be designed so that validation falls inside the application domain.
#2: The designed experiment should involve the full physics of the system, including the loading and boundary conditions.
#3: The solutions of the experiments and from the computational model should be totally independent of each other.
#4: The experiments and the validation process should start from the system level solution to the component level.
#5: Care should be taken that operator bias or process bias does not contaminate the solution or the validation process.

Mechanical Testing of Automotive, Railways, Aerospace components

Installation of mechanical testing structural load frame for carrying out testing high capacity load bearing components. Frames are now available for comprehensive engineering validation of automotive, railways, aerospace components and structures made from polymers, metallic and composite materials.

We can now test and break products and materials from 5N to 500KN.

Discover more at http://www.advanses.com

At AdvanSES, we provide a full 360 degree static and dynamic characterization of your materials, parts and components. We measure the tension, compression, shear, vibration and dynamic properties of individual components and sub assemblies in accordance to international standards.

More information at https://www.advanses.com

Installation of mechanical testing structural load frame for carrying out testing high capacity load bearing components

Mechanical Testing of 3D Printed Parts and Materials

A New Approach to Product Development & Rapid Prototyping

The procedure of manufacturing objects by depositing successive layers upon layers of material, based on 3D digital CAD models, is called Additive Manufacturing (AM) or simply 3D-printing. Fused Deposition Modeling (FDM) technology is one of the most widely used technique in additive manufacturing. A range of other manufacturing materials can be used for 3D printing that include nylon, glass-filled polyamide, epoxy resins, wax, and photopolymers. FDM-based polymer product manufacturing has increased in recent times due to the flexibility it offers in the production of polymer and fibre-based composite parts. FDM-based polymers have the potential to be used in all applications, currently they are primarily used in automotive, aerospace and biomedical applications.

Additive Manufacturing involves a series of processes, from ideation and design development to final product manufacturing using a specialized printer. The different steps depend on the type of manufacturing method and the material type. The primary processes and steps involved are however mostly common and remain the same for different types of manufacturing applications. The steps involved in an AM process are as shown below;

3D Printing Process

Fused Deposition Modeling (FDM)

FDM is the method of choice for manufacturing of 3d printed polymer parts and components due to its simple process, low economic cost and predictable material properties. FDM is already used in the material extrusion manufacturing process for various thermoplastic polymers. Some common thermoplastic filaments used in FDM are acrylonitrile butadiene styrene (ABS), polypropylene (PP), polylactide (PLA), polyamides (PA) like Nylon, polyether-ether-ketone (PEEK) etc. The FDM process consists of the polymer being extruded and deposited in a successive layer by layer method. FDM manufactured polymer parts and components exhibit good mechanical properties, surface finish, and manufacturability. The matrix material used in the FDM process is in the form of a 1.75mm to 2.85 mm filament wound on a spool. The filament is fed into the printer head where it is heated and melted above its glass transition temperature (Tg). The plastic melt is then passed to the nozzle and deposited layer by layer.

FDM of Fibre-Reinforced Polymers


The strength of polymeric materials can be significantly improved through reinforcement by fibres. Fibre-reinforced polymers manufactured using 3d printing technique is gaining traction. Fibre-matrix interaction and porosity are important considerations to be addressed in 3d printing of polymeric composites. FDM is currently the most preferred method for the production of polymeric fiber composites due to its material flexibility, and consistent properties.

Although the 3d printing additive manufacturing method is a sophisticated process for producing materials, and readily usable components and parts, the field service material behaviour of these printed parts is highly complicated. These properties are influenced by several process parameters such as filament material, temperature, printing speed. The material behaviour is highly anisotropic and is governed by the microstructure produced while depositing the layers and the ambient environment. The resulting material behaviour can be described using stress–strain relationships and is critical in the Finite element analysis and stress analysis of models. AdvanSES has full capability to test these complex materials and their behaviours using an array ot techniques. Mechanical testing of 3D printed parts and materials is now a key part of our portfolio of services

Mechanical Testing of 3D Printed Parts and Materials generally involves the following tests:

  1. Uniaxial tension tests
  2. Flexure tests
  3. Compression tests
  4. Poisson’s ration tests
  5. Axial Fatigue tests.

Static and Dynamic Testing of Engineering Materials and Products

Testing of materials and products involves mechanical loading of a material specimen or product up to a pre-determined deformation level or up to the point where the sample fails. The material properties backed out from these tests are further used to characterize the materials and products. Testing is carried out under essentially two conditions viz; Static and Dynamic.

 Physical testing of materials as per ASTM D412, ASTM D638, ASTM D624 etc., can be categorized as slow speed tests or static tests. The difference between a static test and dynamic test is not only simply based on the speed of the test but also on other test variables and parameters employed like forcing functions, displacement amplitudes, and strain cycles. The difference is also in the nature of the information we back out from the tests. Static mechanical testing is carried out at lower frequencies, generally less than one Hertz. The associated loads and applied deformation amplitudes are also smaller and the strain rate is much lower as compared to typical engineering applications. Dynamic loading is generally carried out under forcing functions and with high deformation amplitudes. These forcing functions and amplitudes are applied under a very short time period. When related to polymers, composites and elastomers, the information from a conventional test is usually related to quality control aspects of the materials or products, while from dynamic tests we back out data regarding the functional performance of the materials and products. ASTM D5992, D4092 and D5279 are some of the dynamic mechanical testing standards. High speed tensile, compression, impact, fracture tests using Split Hopkinson Pressure bars (SHPB), Servo-Hydraulic testing machines and cyclic fatigue tests fall under the category of dynamic testing.

 Polymer materials are widely used in all kinds of engineering applications because of their superior performance in vibration isolation, impact resistance, rate dependency and time dependent properties. In some traditional applications they have consistently shown better performance combining with other materials like glass fibres etc., and are now replacing metals and ceramics in such applications. The investigations of polymer properties in vibration, shock, impact and other viscoelastic phenomena is now considered critical, and understanding of dynamic mechanical behaviour of polymers becomes necessary and compulsory.

Figure 1: Static and Dynamic Testing Systems at AdvanSES

The absolute values from frequency sweep, strain sweep, temperature sweep dynamic tests are meaningful, but have little utility as isolated data points. They do become valuable data points when compared to each other or some other known variables. A tan delta or damping coefficient value of 0.4 is poor for a natural rubber or EPDM based compound, but very good in FKM materials where the structure of the compound makes it venerable to lower than optimum dynamic properties. Most uncured rubbery compounds start on the viscous side, and as we cure the compound, we shift towards the elastic side.

 The importance of dynamic testing comes from the fact that performance of elastomers and elastomeric products such as engine mounts, suspension bumpers, tire materials etc., cannot be fully predicted by using only traditional methods of static testing. Polymer and elastomer tests like hardness, tensile, compression-set, low temperature brittleness, tear resistance tests, ozone resistance etc., are all essentially quality control tests and do not help us understand the performance or the durability of the material under field service conditions. An elastomer is used in all major applications as a dynamic part being able to provide vibration isolation, sealing, shock resistance, and necessary damping because of its viscoelastic nature. 

Figure 2: Viscoelastic and Dynamic Studies Correlate Molecular Structure to Manufacturing and Mechanical Properties of Engineering Components

As it stands today, the theory of dynamic properties can be applied judiciously to product development, performance characterization or failure analysis problems. The field of application has evolved over time with availability of highly sophisticated instruments. The problems need to be studied upfront for any time or frequency dependent loading conditions and boundary conditions acting on the components and the theory be suitably applied. Needless to say that dynamic properties have utmost importance when polymeric materials and components show heat generation, and fatigue related field failures. Dynamic characterization relates the molecular structure of the polymeric materials to the manufacturing processes and to the field performance of engineering products. Dynamic properties play an important part in comparing mechanical properties of different polymers for quality, performance prediction, failure analysis and new material qualification. Dynamic testing truly helps us to understand and predict these properties both at the material and component level.

Following are the testing modes that can be implemented and the results for materials and components that one may seek from dynamic testing;

Testing Modes

Test Results Data:

1) Storage or Elastic Modulus (E’) versus temperature, frequency, or % strain

2) Loss or Viscous Modulus (E”) versus temperature, frequency, or % strain

3) Damping Coefficient (Tan Delta) versus temperature, frequency, or % strain

4) Stress vs Strain properties at different strain rates.

5) Strain vs Number of Cycles for a material or component under load control fatigue.

6) Load or Stress vs Number of Cycles for a material or component under strain control fatigue.

7) Fatigue crack growth vs Number of Cycles for a material under strain controlled fatigue.

 No single testing technique or methodology provides a complete picture of the material quality or component performance. It is always a combination of testing methods and techniques that have to be applied to obtain a 360 degree view of the material quality and performance.

References:

1) Ferry, Viscoelastic Properties of Polymers, Wiley, 1980.

2) Ward et al., Introduction to Mechanical Properties of Solid Polymers, Wiley, 1993.

3) TA Instruments, Class Notes and Machine Manuals, 2006.

4) Lakes, Roderick., Viscoelastic Materials, Cambridge University Press, 2009.

5) Srinivas, K., and Pannikottu, A., Material Characterization and FEA of a Novel Compression Stress Relaxation Method to Evaluate Materials for Sealing Applications, 28th Annual Dayton-Cincinnati Aerospace Science Symposium, Ohio, March 2003.

Rubber and Plastic Materials Testing Laboratory

The sole purpose of an engineering laboratory is to provide engineering product development and problem solving services to industries by carrying out controlled condition experiments and engineering analysis. These controlled condition experiments are done using testing machines, computational mechanics tools and advanced engineering softwares. At AdvanSES we use state of the art testing equipments to conduct material testing on any kind of metals, polymers and composite materials. Our computational mechanics tools like Abaqus Finite element analysis software, our in-house machine shop aid us in this process.

Material Testing:


Testing methodologies are primarily divided into two (2) categories depending upon the test rate; static and dynamic. AdvanSES has both static and dynamic testing capabilities. We are able to provide a full 360 degree view of any material or product’s mechanical characteristics. We can also strength, strain, fatigue, hardness, and lots more.

Our testing methods include the following:

1. ASTM D638 – Standard Test Method for Tensile Properties of Plastic

2. ASTM D882 – Standard Test Method for Tensile Properties of Thin Plastic Sheeting

3. ASTM D412 – Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers in Tension

4. ASTM 5992 – Standard for Dynamic Testing of Vulcanized Rubber and Rubber-Like Materials Using Vibratory Methods. Tan delta, storage modulus, loss modulus testing.

5. ASTM D430 – Standard Test Methods for Rubber Deterioration—Dynamic Fatigue

6. ASTM D573 – Standard Test Method for Rubber—Deterioration in an Air Oven

7. ASTM D624 – Standard Test Method for Tear Strength of Conventional Vulcanized Rubber and Thermoplastic Elastomers

8. ISO 6943 – Determination of Tension Fatigue of Rubber and Polymer materials

9. ASTM D395 – Standard Test Methods for Rubber Property—Compression Set

10. ASTM D6147, ISO 3384 – Standard Test Methods for polymer and Rubber Property—Compression Stress Relaxation

11. ASTM D575 – Standard Test Methods for Rubber Properties in Compression

12. ASTM D2990 – Standard Test Methods for Tensile, Compressive, and Flexural Creep and Creep-rupture of Plastics

13. ASTM D1709 – Standard Test Method for Drop Impact Test

14. ASTM D7264 – Flexural Properties of Composites

15. ASTM D3410 – Compression of Composites

16. Hyperelastic Material Characterization for CAE. Mooney-Rivlin, Ogden, Yeoh etc. Constants.

17. Plastic Material Characterization for CAE

18. ASTM E399 and ASTM E1820 – Fracture Toughness Testing

19. High Cycle Fatigue HCF Testing

20. Low Cycle Fatigue LCF Testing

21. ASTM E647 –  Measurement of Fatigue Crack Growth Rates (da/dN)

22. IS 4664 – Standard for Dynamic Testing of Vulcanized Rubber and Rubber-Like Materials Using Vibratory Methods. Tan delta, storage modulus, loss modulus testing.

23. IS 3400 – Standard Test Methods for Vulcanized Rubber and Thermoplastic Elastomers in Tension

24. ASTM D790 and D6272 – 3-Point and 4-point Bend Flexure tests for unreinforced and reinforced thermoplastic and composite materials.

AdvanSES Rubber, Plastic, Composite Materials Testing Laboratory

AdvanSES Mechanical Testing, Analysis & FEA Engineering Services

1) An Independent, design analysis and mechanical testing laboratory.
2) More than 2 decades of product testing and application expertise in mechanical, and materials engineering.
3) State of the art materials and mechanical testing laboratory with qualified engineers.
4) Innovative design, analysis and testing solutions for a wide range of industries

Our Services

1) Mechanical Testing of Polymers, Metals and Composite Materials
2) Fatigue and Durability Testing
3) Dynamic Mechanical Analysis (DMA) of Materials and Components
4) Hyperelastic, Viscoelastic Material Characterization Testing
5) Data Cards for Input into FEA, CAE softwares
6) FEA Services
7) Custom Test Setups with NI Labview DAQ

Material Testing, Product Engineering and Failure Analysis Services

Quality Control and Data Integrity in Mechanical Testing Of Engineering Materials and Products

Quality Control

Quality control refers to the process of systematically detecting errors in the laboratory testing results to ensure both that the accuracy and reliability of test results are maintained and best possible testing results are supplied to customers. Unreliable and inaccurate testing results can result in faulty failures, degraded field performance of engineering materials and products. it is therefore of great importance to ensure all results provided are accurate, reliable and consistent.

Alfort and Beaty define quality control as;

“Quality control is the mechanism by which products are made to measure up to the specifications determined from the customer’s demands and transform into sales, engineering and manufacturing requirements. It is concerned with making things right rather than discovering and rejecting those made wrong. Quality control is a technique by means of which products of uniform acceptable quality are manufactured.”

A mechanical and materials testing laboratory tests all kinds of materials at all stages of product engineering, from the raw material stage to performance characterization and durability testing of finished ready to market products.

The range and types of instruments to test these materials and product range from simplest to complex. Instruments such as density meter and hardness meters are the simple instruments, while SEMs, fatigue test benches, high strain rate equipments etc., are complex instruments that also have a significant learning curve. Only qualified engineers and analysts would be conducting the tests with the help of calibrated instruments to make sure that the data obtained is reliable and accurate.

Achieving quality in a mechanical and materials testing laboratory requires the use of many tools, instruments and machinery. These include UTMs, hardness meters, fatigue testing rigs, and also various custom made test benches. An established maintenance schedule, calibration, quality assurance program, training and quality control are pre-requisites. Calculations and maintenances of QC Statistics for systematic analysis of historical standard deviations, covariances, uncertainty calculations etc., is also required.

Data Integrity

Data integrity refers to completeness, consistency and accurateness of the raw data generated in the testing laboratory during the course of its work. It means that the raw data has to be reliable, consistent and accurate and that no modifications, changes or deletions cannot be caried out by any person or machine.

Raw data in the quality control laboratory can be generated by testing machnes, DAQ systems, and computer systems as well as by laboratory staff as paper records and reports. Ensuring integrity of data starts from the proper design of the procedural documents, level of access provided to authorized persons, physical reliablility of the infrastructure and training of laboratory personnel. An appropriately designed procedure is uniquely named and numbered has sufficient leeway for records to be stored comfortably digitally and physically and distribution are strictly controlled at all levels.

Having established all the QC standard protocols at AdvanSES, we take pride in our work and our protocols are available for audit at any time.