【摘要】：根據(jù)Timoshenko梁理論考慮NiTi回復(fù)應(yīng)力作用,建立了NiTi-Al金屬基復(fù)合材料梁(簡稱復(fù)合梁)的自由振動微分方程,研究了復(fù)合梁的固有頻率調(diào)節(jié)特性.對于懸臂梁,NiTi回復(fù)應(yīng)力使復(fù)合梁呈壓應(yīng)力狀態(tài),造成固有頻率降低,在梁長度80mm、NiTi體積分?jǐn)?shù)8%、預(yù)應(yīng)變3%時,溫度由20℃升至80℃,固有頻率的減小量可達52.1%.對于固支梁,其內(nèi)部應(yīng)力狀態(tài)取決于NiTi回復(fù)應(yīng)力和熱膨脹共同作用,使固支梁固有頻率增加的最小NiTi體積分?jǐn)?shù)約為20%.最后,利用超聲波焊接技術(shù)制造了復(fù)合梁,通過熱模態(tài)實驗測試了NiTi-Al懸臂梁固有頻率隨溫度變化規(guī)律.結(jié)果表明,埋入NiTi能有效調(diào)節(jié)復(fù)合梁固有頻率,且實驗結(jié)果與理論計算結(jié)果規(guī)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，

本文編號：2148115