热环境下复合材料层合梁自由振动分析

Free vibration analysis of laminated composite beam under thermal environment

温度升高导致弹性常数下降。基于Reddy理论,研究热环境下材料常数变化对复合材料层合梁振动特性影响。基于哈密顿原理,推导了Reddy层合梁的动力平衡方程,得到了层合梁的固有频率,分析了长细比对固有频率的影响,对比了热环境下Reddy梁及Euler梁的固有频率。数值结果表明随温度升高,弹性常数下降,Reddy梁对应的固有频率相应降低,而Euler梁的固有频率无明显变化。

The increase of temperature causes the decrease of material constants. Based on the Reddy 's theory,the influences of material constants under thermal environment on vibration characteristics of a laminated composite beam w ere investigated. The equations of motion w ere deduced using Hamilton's principle to obtain natural frequency of the beam and to analyze the effects of length-thickness ratios. The natural frequency of Reddy beam w as compared w ith that of Euler beam under the thermal environment. Numerical results show that elastic constant decrease and natural frequencies obtained from the Reddy's model also obviously decrease w ith the increase of temperature,w hile the natural frequencies calculated from Euler's theory slightly decrease.