【摘要】：傳統(tǒng)的基于幾何非線性假設(shè)的瞬態(tài)熱力耦合計(jì)算方法由于忽略了幾何非線性對(duì)耦合項(xiàng)的影響,在溫度隨時(shí)間劇烈變化的情況下結(jié)構(gòu)傳熱與變形之間存在的耦合關(guān)系不能被真實(shí)的反映。針對(duì)上述問(wèn)題,采用Galerkin和Newmark算法建立了一種能夠在幾何非線性假設(shè)下精確反映溫度劇烈變化情況下結(jié)構(gòu)傳熱與變形間耦合效應(yīng)的瞬態(tài)熱力耦合有限元方法。通過(guò)對(duì)各向正交異性材料薄板在熱環(huán)境下的動(dòng)力學(xué)問(wèn)題的求解驗(yàn)證了該方法的準(zhǔn)確性,并基于該方法對(duì)某型高超聲速飛行器熱防護(hù)系統(tǒng)的蜂窩結(jié)構(gòu)進(jìn)行了瞬態(tài)熱力耦合計(jì)算。結(jié)果表明:熱力耦合項(xiàng)使溫度變化產(chǎn)生很小的波動(dòng),導(dǎo)致溫度變化率發(fā)生震蕩,其振動(dòng)幅值與耦合項(xiàng)相關(guān);熱力耦合項(xiàng)對(duì)結(jié)構(gòu)振動(dòng)起到衰減作用,使結(jié)構(gòu)形變速度趨于衰減,其衰減程度與結(jié)構(gòu)溫度成正比;幾何非線性假設(shè)對(duì)增大結(jié)構(gòu)溫度變化率振幅作用顯著,并且能夠增大結(jié)構(gòu)振動(dòng)速度,影響熱結(jié)構(gòu)變形大小。
[Abstract]:Because the influence of geometric nonlinearity on the coupling term is neglected in the traditional calculation method of transient thermodynamic coupling based on geometric nonlinearity assumption, The coupling relationship between heat transfer and deformation of the structure can not be truly reflected when the temperature varies dramatically with time. In order to solve the above problems, a transient thermal-mechanical coupled finite element method is developed by using Galerkin and Newmark algorithms, which can accurately reflect the coupling effect between heat transfer and deformation of structure under the assumption of geometric nonlinearity. The accuracy of this method is verified by solving the dynamic problems of orthotropic thin plates in different directions in thermal environment. Based on this method, the transient thermodynamic coupling calculation of honeycomb structure of a hypersonic vehicle thermal protection system is carried out. The results show that the thermo-mechanical coupling term causes the temperature change to fluctuate very little, resulting in the oscillation of temperature change rate, and the amplitude of vibration is related to the coupling term. The thermal coupling term attenuates the vibration of the structure, which makes the velocity of deformation tend to attenuate, and the attenuation degree is proportional to the temperature of the structure. The geometric nonlinearity hypothesis plays a significant role in increasing the amplitude of the temperature change rate of the structure, and can increase the vibration velocity of the structure and influence the deformation of the thermal structure.
【作者單位】： 西北工業(yè)大學(xué)航天飛行動(dòng)力學(xué)技術(shù)重點(diǎn)實(shí)驗(yàn)室;
【分類號(hào)】：O343.6
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本文編號(hào)：2400335