Search Results for test standards

Development of international antibacterial standards will greatly benefit society by helping industry produce goods with better antibacterial, anti-biofilm, an anti-biofouling properties.

Measuring material properties is disproportionately more complex for fiber-reinforced composites than for materials such as metals and plastics. It is further complicated by more than 150 composite test standards in use around the globe. This article assesses the challenges involved in testing fiber-reinforced composites and presents a rational approach for specimen preparation, handling, and fixturing that can simplify testing and improve throughput without sacrificing measurement accuracy.

This article identifies several factors that are not fully addressed in most fracture toughness test standards and explains how they may influence calculated values obtained from ferritic steels. Of particular consequence are test temperatures within the ductile-to-brittle transition regime and test specimen geometries when measuring the toughness of weld metal and heat-affected zones.

As demand for adherence to VDA standards increases, aluminum testing equipment keeps pace. The VDA, or Verband der Automobilindustrie, is the German association of the automotive industry. Typically, the VDA requirements are adaptations to existing ISO standards with more stringent requirements that aim to reduce variability between labs.

Successful use of composite materials requires a thorough understanding of their mechanical properties. Although a range of mechanical tests is required to obtain data, the aerospace industry has already developed, validated, and standardized these test methods. This article reviews some of key test methods used with composites.

Steel rebar is commonly used around the world to reinforce concrete. Understanding the basics of rebar tensile testing is critical to ensuring product quality. This article addresses issues in rebar tensile testing that are commonly misinterpreted or misunderstood by users.

A set of standardized material specifications and test methods now exists to evaluate and maintain quality in shape memory alloys used for medical devices and actuators. This article summarizes the ASTM standards applicable to shape memory technology in medical and actuation applications, and identifies areas requiring further standardization work.

Non-contacting extensometry offers a wide range of benefits in materials tests. Depending on the specific application, non-contacting extensometry may be the only option for strain measurement.

Resonant ultrasound spectroscopy (RUS) is an emerging ultrasonic measurement technique. By measuring the natural vibrational frequencies of test samples, RUS can determine Young's modulus, shear modulus, and Poisson's ratio for isotropic materials. By comparing the vibrational spectra of a test sample to those obtained from a standard, it is possible to infer the causes of the differences (if any) and detect various part defects, such as size variations, cracks, and pores. Thanks to advances in computer technology, codes and software are now available for data reduction, analysis, and interpretation. This article addresses fundamentals of the technology and applications in research and industry.

With the goal of improving aircraft efficiency, Boeing in collaboration with NASA Glenn Research Center (GRC) have developed and successfully flight tested environmentally activated vortex generators that passively, repeatedly, and accurately retract during cruise and deploy during take-off and landing phases. The capability discussed in this article is based upon recent advancements in shape memory alloy rotary-actuation technology, which included improved alloy systems, design tools, best practices, published standards, and previous wind tunnel and flight test demonstrations.

Because alloy steel hardenability is such an important factor in part manufacturing, the Center for Heat Treating Excellence (CHTE) is conducting research through simulations and laboratory testing aimed at learning more about the performance of gas quenching systems used to harden newer alloy steels. The primary goal of the study is to establish a standard method to evaluate gas-quench steel hardenability. Heat transfer coefficients will be determined for different gas pressures and during the cooling phase.

New methods evaluate steel hardenability in a standard gas quench test and heat transfer coefficient variation within a furnace gas quench chamber.

Recently developed open-source software based on standard test and normalization methods simplifies the process of generating J-integral versus crack-growth resistance (J-R) curves to evaluate fracture toughness in the ductile region.

The Center for Heat Treating Excellence (CHTE) at Worcester Polytechnic Institute (WPI) in Massachusetts is conducting a cutting-edge research project aimed at measuring the surface hardness and case depth on carburized steels for process verification and control. The results will enable companies to improve the quality of heat-treated products faster and more cost-effectively. Nondestructive techniques being evaluated initially include eddy current, meandering winding magnetometer (MWM), Barkhausen noise testing, and alternating current potential drop.

Compared with traditional fatigue testing, the ultrasonic method achieves much speedier results along with the ability to run extremely high test cycles in a reasonable time frame.

3D laser microscopy is opening new areas of study for metallic alloys and coatings in power generation applications. This article describes some case studies where laser microscopy has augmented, and in some cases replaced, metallic alloy characterization using optical microscopy or scanning electron microscopy.

Existing strain measurement techniques do not offer enough information about how failures occur, so alternative methods are needed. One technique involves using digital image correlation (DIC) to measure full field strain over the entire material surface. DIC works by capturing a series of images throughout a test and analyzing them afterwards.

This article discusses the capabilities of a compression test system developed to evaluate composite coil springs for automotive suspension systems.

Compared to traditional power plant materials, creep strength enhanced ferritic steels require new approaches to nondestructive examination and weld repair. The metallurgical complexity of these steels prompted EPRI to conduct research to define and/or improve the detection limits of ultrasonic testing techniques, explore novel electromagnetic techniques, evaluate the sensitivity and applicability of acoustic emission testing, and conduct studies on improved weld repair procedures.

With today’s sophisticated measurement technology and testing equipment, manufacturers need never be in doubt over the quality of their starting materials and any property changes that occur in process. This interview addresses some of the key processes and technologies used to verify material stocks.