Stress and strain measurements by image correlation and Thermoelasticity
In this paper image correlation and thermoelaticity are proposed as joint measurement techniques to perform a “full field” characterization of materials and mechanical components. The very interesting possibilities offered by using both these non contact measurements techniques is the ability to obtain, by measuring both stress and strain, distributions of mechanical parameters on the surface of a dynamically loaded mechanical component, made, in general, of any material. This kind of results can be very useful for non homogeneous, composite or complex materials, or for complex shapes or loading conditions of the mechanical component under analysis, nowadays largely used for machine and structure realizations. In the work a proper coating, useful to perform measurements by both the techniques, is developed and tested. The coating act as a stressstrain distributed gauges.
TSA infrared measurements for stress distribution on car elements
Abstract. Because of the continuous evolution of the market in terms of quality and performance, the car production industry is being subjected to more and more pressing technological challenges. In this framework the use of an advanced measurement technique such as thermoelasticity allows the engineers to have a fast and reliable tool for experimental investigation, optimization and validation of the finite element method (FEM) of those critical parts, such as parts of car-frame tables (Marsili and Garinei, 2013; Ju et al., 1997). In this work it is shown how the thermoelastic measurement technique can be used to optimize a Ferrari car frame, as a method of experimental investigation and as a technique of validation of numerical models. The measurement technique developed for this purpose is described together with the calibration method used in the test benches normally used for fatigue testing and qualification of this car's components. The results obtained show a very good agreement with FEM models and also the possibility of experimentally identifying the concentration levels of stress in critical parts with a very high spatial resolution and testing the effective geometry and material structure.
Global Occupational Health Issues
1. Occupational health problems in developing countries are more widespread and serious because they occur against a background of endemic risk factors for ill health. 2. In general, developing countries have less adequately developed occupational health personnel and programs and less adequately developed and enforced laws and regulations than developed countries. 3. Awareness of the importance of occupational health among workers, management, government officials, and the public is increasing with developing countries. 4. Occupational health professionals in developed countries can contribute in many ways to improving occupational health in developing countries.