#DESIGN-AND-TESTING

Testing

Strain measurement in composites testing

Columnist Dan Adams explores the most important considerations and most common methods for strain measurement.

Testing

Mechanical testing of textile composites

Standardized mechanical testing methods abound, but they often focus on composites with unidirectional layers. Here are some modifications to common test methods for testing textile composites.

Defense

Measuring thermoplastic prepreg tape quality for part process control

Low-cost tests measuring dimensions, thermal behavior and consolidation predict CFRTP part quality.

Testing

Environmental testing of composites

Additional testing of polymer matrix composites (PMCs) is often performed in alternate environmental conditions to determine properties related to temperature and moisture sensitivity.

Thermoplastics

Design engineering of tailored preforms

Tailored preforming has opened new doors in composites fabrication, but designing for it requires tools that understand and work with this complex process.

Testing

Composite material testing: How do I know if my measured composite properties are correct, or even reasonable?

CW columnist Dan Adams explores methods for determining correctness of measured mechanical properties for fiber-reinforced composites.

Testing

Glass transition temperature testing of composites

The glass transition temperature of polymer matrix composites (PMCs) is determined by a series of tests at increasing temperatures.

Design/Simulation

Overcoming barriers to adoption of structural autocomposites

Although much attention has been focused on material costs and development of high-rate, automated manufacturing processes for structural autocomposites, production of viable products depends on the ability to design and simulate the structures for these exciting new FRP applications. 

Testing

Shear testing of high-shear strength composite laminates

CW columnist Dan Adams compares three V-notched shear test configurations used to measure the shear stiffness and shear strength of composite materials.

Testing

Fiber-optic sensors shed light on the toughest composite design challenges

Designers of composites are learning that if they are to be able to guarantee component and system performance, repeatability and reliability, it is critical that they have access to more sensor and test data.

Testing

Gripping composite test specimens: Options and guidance

Orthotropic behavior of composites test specimens makes load introduction uniquely challenging.

Testing

Application of video extensometry to ASTM D 5656

Reliable, reproducible data is central to the design and delivery of cost-effective bonded assemblies.

Testing

What’s the most important type of mechanical test for composites?

 When the opportunity arises, I like to ask those familiar with composites testing this question: What type of mechanical test do they consider to be the most important for composite materials?

Aerospace

Tackling the traceability of composite materials

Have you ever looked outside an airplane window during in-flight turbulence and wondered how strong the wings really are and how much load they can take?

Testing

Can flexure testing provide estimates of composite strength properties?

Flexure tests are simple to perform, yet the state of stress and failure modes are among the most complex.  

Aerospace

Software has a critical role in certification of composite designs for aerospace

Despite the many advantages that come with using composites materials in aerospace applications, designing weight-bearing structures from these materials remains a significant challenge.

Testing

Choosing composite material testing methods

An initial step in selecting suitable test methods involves consulting the available test literature. 

Testing

How ready are progressive damage analysis tools?

In the past 15 years, progressive damage analysis (PDA) for composites, implemented in finite element analysis software, has been under development.

Testing

Best practices for V-notched shear testing of composites

In my October 2015 column, I wrote an overview of the widely used V-notched shear test methods for composite materials. In this column, we focus on some additional best practices when performing V-notched shear testing of fiber-reinforced composites.

Testing

X-rays for NDT of composites

Nondestructive test (NDT) methods can be employed during the design, manufacture and in-field maintenance of composite components.

Testing

Damage tolerance testing of composites

Not standardized until 2005, ASTM D 7137 is still commonly referred to as the Boeing CAI test.

Carbon Fibers

CompoSIDE and Trace: Game-changer for development of composite parts

Structural design challenges (delamination, coupling and shape distortions, resin-driven failures, local stress concentration and the like) are inherent in laminate architecture. The author's contention is that a solution can be found in design simplification afforded by the work of Dr. Stephen Tsai in Trace-based analysis.

Testing

Fracture mechanics testing of composites

Dr. Daniel O. Adams, professor of mechanical engineering and director of the Composite Mechanics Laboratory at the University of Utah, and vice president of Wyoming Test Fixtures Inc. (Salt Lake City, UT, US), addresses ways to acquire mechanical test data and then calculate the values for the composite material property of fracture toughness.