The NMISA upgraded its impulse hammer calibration system to satisfy new demands from local industry for shock force measurements. As part of Land Mobility Testing (LMT), high impact force levels are measured. Improvements to the existing facility required the development and implementation of a system, able to deliver repeatable high impact forces, with a substantial payload. Further improvements included the development of a data capturing unit for the measurement of the impact pulses and to determine the unit under test shock force sensitivity. This paper will discuss the measurement...
It is widely known that in the primary calibration of accelerometers by using a laser interferometer, a unit under test (UUT) and the laser interferometer should measure vibration at the same position. However, this is not applicable to single-ended accelerometers because of the limitation of their design. One way of overcoming this limitation is to measure the vibration at several positions on the plate which connects UUT to a vibration exciter. However this can present the effects of rocking motions of the exciter. Although the motions of vibration exciters are presented in several...
This paper presents a testing method and process of damping properties of a kind of damping material. A damping system was regarded as the experimental subject composed of an oblate solid cylinder specimen of the damping material and an additional mass. The specimen is excited by an electromagnetic shaker in the vertical direction, and the specimen excites the additional mass vibrating. Not only the traditional damping properties, such as the damping ratio and vibration transfer rate, but also the nonlinear properties are measured to evaluate the damping specimen. Firstly the...
The traceability to the acceleration measurements for the industry is done in France by the LNE. This traceability to the national standards is necessary for the industries that have processes where knowledge of the parameters related to the acceleration is essential in terms of quality and safety, such as nuclear, space, automotive or military fields. The reference accelerometers calibrations for the industry and other laboratories are performed at the LNE's site located in Trappes since 2006 by the absolute method using a Michelson interferometer. However, the equipment used, presented in...
The Center for Measurement Standards provides two test pieces for this exercise to compare a set of common data including elastic modulus and indentation hardness. Participating laboratories will perform the common test items on their systems and follow the recommended instructions. The distribution chart compiled from the experiment data provided by each laboratory can then be used to fully demonstrate the current state of nanoindentation testers. The experimentation method shall take the testing capabilities of each laboratory into consideration, and a full analysis shall be provided. The...
The Primary Rockwell Hardness Standard System was set up in the Center for Measurement Standards since July 1996 till June 1997. During the time, a laser interferometer, HP10737R 3-axis compact interferometer system was used to measure the effect of pitch and yaw of the Rockwell Hardness machine. As the laser interferometer was performed the measurement of the pitch and yaw of the indenter when the hardness was measured; then we evaluated the uncertainty caused from the Abbe's error through pitch and yaw measurements. In this paper, we will compare the results to the results of 2003 and to...
Instrumented indentation test is a simple and effective method for evaluating the mechanical properties such as elasticity/stiffness, hardness and adhesion. During indentation test, materials are subjected to highly localized stresses. It is fundamental interest to explore its mechanical properties under conditions of extreme contact pressure. Raman micro-spectroscopy is a powerful and rapid technique to investigate the pressure-induced phase transformations and the residual stress in the indented region. This technique has been successfully used to study pressure-induced phase transitions...
There are increasing demands for measuring mechanical properties of small volumes of metal or smallsized materials used for Micro-Electro-Mechanical-Systems (MEMS). This is basically because such mechanical properties are closely related to the strength and reliability of the metal or systems. In this work, a nanoindentation technique with a spherical-tip is applied to the evaluation of elastic-plastic properties such as stress-strain relationship of industrial materials such as steel and aluminium. A continuous multiple loading method is employed to determine the stress-strain curve. A set...
Over the past years a large number of papers have been published on the application of the nanoindentation method. These works describe various aspects of the nanoindentation method and provide a detailed overview of the characteristics of different hardware and software tools implementing this method. However, measurements taken under the same conditions and on the seemingly same samples often provide a significant discrepancy in the results on different instruments functioning according to the same principle. This paper discusses the issues of metrological support for the nanoindentation...
Instrumented indentation has now become established for the single point characterization of hardness and elastic modulus of both bulk and coated materials. This makes it a good technique for measuring mechanical properties of homogeneous materials. However, many composite materials are composed of several phases whose properties are difficult or even impossible to examine in bulk form ex situ (e.g., carbides in a ferrous matrix, martensite and austenite in steels, etc.). The requirement for in situ analysis and characterization of such structured materials with different phases obviates...