自行火炮扭力轴载荷谱的测量及疲劳寿命预测

为预测自行火炮扭力轴寿命，对某型自行火炮在不同工况下进行实车试验，获得了多工况下扭力轴的载荷谱。受力分析表明，表面最大拉应力是扭力轴的破坏应力；提出基于随机响应面对扭力轴寿命进行预测的方法，将低周疲劳寿命表达式中的随机参数表示为标准随机变量，引人随机响应的Hermite多项展开式进行拟合，建立了扭力轴疲劳寿命的显式函数。通过对实测载荷谱进行统计分析，依据寿命表达式可以预测扭力轴疲劳寿命，并给出概率分布。该方法弥补了传统响应面法以一般多项式拟合时不能保证收敛性的缺陷。

Load Spectrum Measurement and Fatigue Life Prediction of Torsion Shaft of Self-propelled Guns

In order to predict the fatigue life of torsion shaft of self-propelled gun, an experiment has been carried out through field test to achieve the load spectrums of torsion shaft. The conclusion that the maximum tensile stress is the failure stress of torsion shaft is drawn. The stochastic response surface method （SRSM） is introduced to study the low cycle fatigue life of torsion shaft. The stochastic parameters of low cycle fatigue life are expressed to stochastic variables, and the structural stochastic response is fitted based on Hermite polynomials. The function of the low cycle fatigue life of torsion shaft is achieved. The results show that the SRSM can achieve the statistical information of the structural stochastic response rapidly and accurately.