由于汽车排气管在实际运行环境中受到复杂交变载荷,单轴的疲劳试验不能准确预测试件的疲劳寿命。双轴的协同加载能更好地模拟实际工况,但需要对两个轴力传感器输出信号的幅值和相位差进行精确控制。因此,针对排气管双轴动态加载的需求,...由于汽车排气管在实际运行环境中受到复杂交变载荷,单轴的疲劳试验不能准确预测试件的疲劳寿命。双轴的协同加载能更好地模拟实际工况,但需要对两个轴力传感器输出信号的幅值和相位差进行精确控制。因此,针对排气管双轴动态加载的需求,研发一种力控制的电液伺服式双轴疲劳试验加载装置,并设计基于PXI总线结构和多DSP并行处理技术的多轴伺服控制器,基于伺服闭环和外环驱动谱修正相结合的控制算法,实现了双通道正弦波的幅值相位控制。为验证算法的性能,两通道参考信号均采用频率为10 Hz,幅值为2. 363 k N的正弦波,并且相位差为90°,对排气管进行双轴疲劳试验。试验结果表明:该双轴力加载系统能精确地跟踪参考信号的幅值和相位差。展开更多
Two different types of experimental techniques to perform non-isothermal, uniax-ial and biaxial fatigue tests were described. A new miniaturised electrothermal-mechanical test rig was presented and discussed. It enabl...Two different types of experimental techniques to perform non-isothermal, uniax-ial and biaxial fatigue tests were described. A new miniaturised electrothermal-mechanical test rig was presented and discussed. It enables testing of small specimens under complex thermomechanical loading conditions. In order to cope with the simulation of well defined biaxial proportional and non-proportional loadings with in-phase and out-of-phase superposition of thermal loads a cruciform biaxial fatigue testing machine has been developed. Special design features of both machines, and the specimens tested, as well as typical test results were discussed.展开更多
文摘由于汽车排气管在实际运行环境中受到复杂交变载荷,单轴的疲劳试验不能准确预测试件的疲劳寿命。双轴的协同加载能更好地模拟实际工况,但需要对两个轴力传感器输出信号的幅值和相位差进行精确控制。因此,针对排气管双轴动态加载的需求,研发一种力控制的电液伺服式双轴疲劳试验加载装置,并设计基于PXI总线结构和多DSP并行处理技术的多轴伺服控制器,基于伺服闭环和外环驱动谱修正相结合的控制算法,实现了双通道正弦波的幅值相位控制。为验证算法的性能,两通道参考信号均采用频率为10 Hz,幅值为2. 363 k N的正弦波,并且相位差为90°,对排气管进行双轴疲劳试验。试验结果表明:该双轴力加载系统能精确地跟踪参考信号的幅值和相位差。
文摘Two different types of experimental techniques to perform non-isothermal, uniax-ial and biaxial fatigue tests were described. A new miniaturised electrothermal-mechanical test rig was presented and discussed. It enables testing of small specimens under complex thermomechanical loading conditions. In order to cope with the simulation of well defined biaxial proportional and non-proportional loadings with in-phase and out-of-phase superposition of thermal loads a cruciform biaxial fatigue testing machine has been developed. Special design features of both machines, and the specimens tested, as well as typical test results were discussed.
