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早在1936年 Q.Fppl 曾建议以减振性来评定金属在交变载荷下的微量塑性变形能力,并设计出测试设备。以后,某些学者用与 Q.Fppl 相同的测量方法测得衰减振动性能并定义为“动塑性”以区别于静荷塑性。1938年以滞后环测量来研究交变载荷下的塑性变形。但是,由于测量仪器及设备的限制,仍然没有测出这一在交变载荷下的重要性能指标。在国外,通过测量滞后环变化或衰减率变化的方法,在研究疲劳过程及其本质问题上已取得了一定的成就。如测量滞后环的变化来研究疲
As early as 1936, Q.Fppl had proposed damping capacity to assess the micro-plastic deformation capacity of metals under alternating loads and to design test equipment. Later, some scholars measured the decay vibration performance with the same measurement method as Q.Fppl and defined as “dynamic plasticity” to distinguish it from static load plasticity. In 1938 the hysteresis loops were measured to study the plastic deformation under alternating load. However, due to the limitations of measuring instruments and equipment, this important indicator of performance under alternating load is still not measured. Abroad, by measuring the change of hysteresis loop or the change of attenuation rate, some achievements have been made in the study of the fatigue process and its essence. Such as measuring changes in the hysteresis loop to study fatigue