Dimensional measuring of parts as function of temperature variation and FEM study

Abstract

The components of astructure can be made in many different areas by many suppliers, before being brought together as a single final. Measuring geometry and geometric dimensions of a structure is an essential process in establishing product quality. Dimensional measurement is often affected by several human or physical factors, of which temperature is an essential factor in introducing deviations. Often the expected results are out of specification due to temperature variation. Paper aims to present the effects due to temperature variations in dimensional measurement as well as way to solve problems. One of the problems in the measurement process is the lack of repeatability in measuring tolerated dimensions. The study presents measurements in the conditions of volumetric thermal expansion of AMCs and measured parts, which are directly influenced by temperature. The need to verify the accuracy of measurements and control of equipment is an important step for quality departments in this industry because the quality of production is based on the target of “zero defects” so the need to know about the condition of equipment is extremely important. In specific cases in addition to the normal calibration which is according to international standard ISO 10360-2: 2009 as a mandatory application, the same standard determines the need to perform re-verification tests according to user specifications, looking for deviations that should not occurs in systematic errors. Also, the international standard ISO 17025: 2005 which defines the general requirements for testing and calibration components of laboratories, in point 5.5.10 of the technical requirements it is said that intermediate checks are necessary to maintain confidence in the calibration status of equipment, these checks having to be done according to a specific procedure. Three techniques for assessing measurement uncertainty are presented in ISO 15530-; they can be used alone or in combinations. The first of these is known as sensitivity analysis and is described in the ISO Guide for Expressing Uncertainty in Measurement. Modeling and simulation can help evaluate the size of a part as a function of temperature. The article presents in the second part this method which offers values very close to the experimental ones and which may in the future simulate the values of the measurements where the experimental part is difficult to be done.