论文部分内容阅读
本文探讨了多种机械性能试验中试样与试验机间弹性相互作用的重要性,并考虑到普通的计算机器刚性的缺点。提出两种有效计算试验机刚性的表达式,它实际是一种复合刚性包括机器,夹头或压板、负荷传感器,绝缘与润滑剂。刚性是从LASL凸轮塑性计上进行压力试验所获得的数据中计算出来的。其导出式可用于计算多种类型的程序试验机的刚性;而且亦可适用于横梁速度恒定的试验机的拉伸与压力试验。在LASL凸轮塑性计上进行了200余次试验计算其刚性,在横梁速度恒定试验机上进行了几次压力试验与几次拉伸试验。从这些计算的结果中可得出结论即试验机的刚性是个变量,一般来说它随施加负荷之增长而增长。最后,因为相同试验状况下计算出来的刚性可能有很大的差异,故应对每次力学试验进行刚性计算。只有这样做才能从负荷——时间或负荷——位移数据中推算应力——应变曲线时计及试样——机器的相互作用。
This article discusses the importance of the elastic interaction between the specimen and the tester in a variety of mechanical performance tests, and takes into account the shortcomings of common computing device rigidity. Two expressions that effectively calculate the rigidity of the tester are proposed. It is actually a kind of composite rigidity including a machine, a chuck or a press plate, a load sensor, an insulation and a lubricant. Rigidity was calculated from data obtained from pressure tests on a LSL cam plastometer. Its derivation can be used to calculate the rigidity of various types of program testers; it can also be applied to tensile and pressure tests of testers with constant beam speeds. More than 200 tests were performed on the LSL cam plastometer to calculate its rigidity. Several pressure tests and several tensile tests were performed on a constant beam tester. From the results of these calculations, it can be concluded that the rigidity of the test machine is a variable, which generally increases with the increase of the applied load. Finally, because the stiffnesses calculated under the same test conditions can vary widely, it is important to perform a rigid calculation for each mechanical test. Only by doing so can the stress-strain curve and specimen-machine interactions be extrapolated from the load-time or load-displacement data.