NiTi-Al金属基复合材料梁固有频率调节特性理论与实验研究

发布时间：2018-07-27 14:26

【摘要】：根据Timoshenko梁理论考虑NiTi回复应力作用,建立了NiTi-Al金属基复合材料梁(简称复合梁)的自由振动微分方程,研究了复合梁的固有频率调节特性.对于悬臂梁,NiTi回复应力使复合梁呈压应力状态,造成固有频率降低,在梁长度80mm、NiTi体积分数8%、预应变3%时,温度由20℃升至80℃,固有频率的减小量可达52.1%.对于固支梁,其内部应力状态取决于NiTi回复应力和热膨胀共同作用,使固支梁固有频率增加的最小NiTi体积分数约为20%.最后,利用超声波焊接技术制造了复合梁,通过热模态实验测试了NiTi-Al悬臂梁固有频率随温度变化规律.结果表明,埋入NiTi能有效调节复合梁固有频率,且实验结果与理论计算结果规律一致.
[Abstract]:Based on the theory of Timoshenko beam, considering the effect of NiTi recovery stress, the differential equation of free vibration of NiTi-Al metal matrix composite beam (NiTi-Al composite beam) is established, and the natural frequency regulation characteristics of composite beam are studied. For cantilever beam, the recovery stress of Niti causes the composite beam to be compressive stress state, resulting in the reduction of natural frequency. When the length of the beam is 80 mm and the Niti volume fraction is 8, the temperature increases from 20 鈩，

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