利用机械结构的振动加速度信号反算应变的新方法

针对结构紧凑的机械结构难以采用布置应变计的方法来测量应变的问题,从动力学角度出发,采用虚拟力技术建立了实际作用力的等效力。通过进行虚拟测点的计算,以解决实际测点不足的难题。提出了加速度响应信号与输入载荷的协调方程,利用运行状态下机械结构的加速度响应信号来反算结构应变的方法。并通过工程实例得以验证。研究结果对结构紧凑、不利于进行应变测试的部位,可采用该方法进行应变数据的分析,为进行疲劳寿命分析奠定基础。

A new method for calculating strains of a mechanical structure using its vibration acceleration signals

In order to solve a difficult problem to locate strain sensors on a compact mechanical structure to measure its stress, based on dynamics, equivalent forces of actual forces were built using the pseudo-force technique, and pseudo measurement points were arranged on the mechanical structure to overcome lack of measurement points. A new method to calculate structural strains using acceleration response signals of the mechanical structure under operation was put forward and verified by engineering examples. The study results showed that the new method could be used to analyze the strain data of a compact mechanical structure which was not suitable for strain measurement. The proposed method laid a founda-tion for fatigue life analysis.