可靠地测试疲劳特性

当对材料进行安全性预测,尤其是计算其使用寿命时,就需要获得可靠的材料参数。当处于高频应力环境或在长达 30 年的运行时间内,汽车工程、医学和能源技术中的结构在其服役期间将经历超过千万次循环的负载变化。该范围被称为超高周疲劳 (VHCF)范围,远远超出典型的 S-N 曲线范围。因此,若使高性能部件能在 VHCF 范围内可靠运作,则必须大量掌握所用材料的疲劳特性知识。

至于验证有限元模型,Polytec 的 3D扫描式激光测振仪可直接获取实际疲劳样本的本征模态和本征频率。另一个潜在应用是高频应力和应变分析领域,因为传统的接触式应变计不适用于这种耐久应力的测试。To be able to go through the high load changes of 1010 in a reasonable time period of less than one month, the samples are offset in resonance vibration at frequencies in the kHz range.

Measuring stress and strain and Eigen modes

With regard to verifying the simulated sample model, Polytec 3D Scanning Vibrometers provide a direct way of measuring the true fatigue sample’s Eigen modes and Eigen frequencies. Another potential application lies in the field of high-frequency stress and strain analysis, since contact measurement methods such as strain gages are not suitable for this type of endurance stress. This method also comes into play for operational reliability testing of high-stress train components (wheel rims), wind turbines and ultrasonic scalpels (medical technology).

Your PolyXpert in Vibrometry