Search Results for full field strain

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.

Recent advances in hardware and software provide materials testers with improved productivity and enhanced capabilities. This article describes some innovations in testing composites and aluminum alloy formability and new capabilities in digital image correlation and testing machine software.

Digital image correlation data and Bayesian inference used together facilitate rigorous quantification of the uncertainty in material input parameters for finite element simulations of superelastic deformation.

Researchers at the University of Michigan are investigating the complex heterogeneous phase transformations associated with deformation in shape memory alloys by means of in-situ tensile loading in combination with SEM, EBSD, and digital image correlation. This article describes the general approach and presents and interprets test results.

New research explores a zirconia-based shape memory ceramic that exhibits a unique type of electrically triggered martensitic transformation.

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.

Residual stress is generally defined as the stress that is retained in equilibrium in a body or material after manufacturing or processing operations or component usage in the absence of any external forces. This article provides an overview of residual stress measurement methods, including diffraction-based, piezo-spectroscopic/Raman, mechanical, ultrasound, and magnetic techniques. It includes a discussion of measurement planning and execution considerations.

The ability to produce bulk metallic nanolaminates has greatly expanded the potential structural applications for these materials, motivating investigations into formability, joining techniques, and deformation behavior. This article presents an overview of both the accumulative roll bonding process and the deformation behavior for copper-niobium nanolaminates. This entry won the Jacquet-Lucas Award for Best in Show at the 2014 International Metallographic Contest.

Laser shock peening is a novel surface engineering method that improves component performance by introducing deep compressive residual stress. It has demonstrated significant benefits in safety-critical applications such as aerospace engines. Ongoing research focuses on lowering the cost and increasing equipment flexibility.

Raman spectroscopy is an indispensable tool in laboratories conducting research in the nascent field of carbon nanomaterials. It provides comprehensive information about the structure and layer thickness of graphene samples with high levels of sensitivity, stability, and control.

This article provides an overview of nondestructive test methods and their application in the study of material properties and structures. It covers the most widely used NDT technologies, including optical examination, radiography, acoustic emission, and ultrasonic testing, and discusses the impact of recent advancements.

This article series explores the indispensable role of characterization in the development of cold spray coatings. Transmission electron microscopy is used to understand powder characteristics, cold spray coating deformation behavior both within splats as well as near the coating-substrate interface, phase transformations in the as-sprayed and heat treated conditions, phase equilibria of the coating under the operating conditions pertaining to the application of the coating, the coating recovery mechanism, and the thermal stability of the coating.

Computer modeling is used in the design and development stages of induction hardening to optimize the process and to improve component quality including hardness, beneficial stress distributions, and reduced distortion.

A unique collaboration brings together university and industry stakeholders to conduct basic and applied physical metallurgy research on nonferrous structural alloys. This article provides a brief overview of the Center for Advanced Non-Ferrous Structural Alloys (CANFSA), summarizes current research efforts, and describes the types of industry-university interactions within CANFSA.

Field assisted sintering is a breakthrough technique for producing aluminum matrix composites that could replace high-density materials in a variety of applications.

High-speed, high-fidelity techniques used to analyze texture and dislocation content enable greater understanding of the influence of texture on deformation of titanium alloys than previously possible. This article describes a study in which specimens were examined using graphical slip band analysis to understand the influence of microstructure, alloy content, and loading orientation on the surface deformation response of titanium.

Wavelength-dependent or hyperspectral imaging is a novel nondestructive characterization technique in the field of neutron radiography and computed tomography. A dedicated facility named VENUS is currently being built at Oak Ridge National Laboratory to provide these characterization capabilities for academia, industry, and other national laboratories. This feature article describes the VENUS capabilities for materials science and engineering, provides a quick overview of the modes of access of the facility, and illustrates the nondestructive measurements and interpretation of results.

A look at how companies in regulated industries can test materials to produce higher quality metal components with additive manufacturing.

Engineering departments at universities across the U.S. are using materials testing to advance scientific research. Five innovations under development are presented here, including work on advanced materials to improve building integrity and to enhance medical treatments.

New FDA guidance for Nitinol used in medical devices includes clarification on the determination of safety factors, the requirements for corrosion testing, and proper labeling of potentially harmful elements.