夹层结构屈曲模型的拓展及失效判据

Development of buckling model and failure criterion of sandwich structure

现存有许多种关于预测夹层结构在承受压缩/弯曲载荷时屈曲临界值的理论模型。在这些模型中,鲜有研究者在模型中考虑面板在屈曲过程中横向剪切所造成的影响。除此之外,现存屈曲公式的特点为:经典公式形式简单但精度低、适用范围小;一些模型精度高但形式复杂,不便于直接工程应用。因此,首先建立了一种基于弹性理论求解屈曲问题的新理论模型,模型中引入了面板的横向剪切效应并评估了剪切效应对屈曲载荷造成的影响。然后,通过在不同屈曲波长范围内对精确解进行简化,建立了在不同屈曲波长范围内的近似解模型,并评估了近似解的精度和适用范围。最后,建立了一个新的夹层结构屈曲失效判定准则,新准则具有更高的精度且形式简洁,易于工程应用。

There exist many theoretical models for predicting the critical buckling values of sandwich structures under compression/bending loads.In these models,few researcher has taken into account the effect of transverse shear on the face layers during buckling.In addition,the characteristics of the existing buckling formulas are as follows:classic formulas are simple in form but have low prediction accuracy and a narrow range of applications,and thus not convenient for users;some models s have high accuracy but complex forms,and are not convenient for direct engineering application.In this paper,we establish a new theoretical model for solving the problem of buckling based on the elastic theory.In the new model,the transverse shear effect of the face layer is taken into account for the first time,and the influence of shear effect on the buckling load is evaluated.By simplifying the exact solutions in different buckling wavelength ranges,we establish the approximate solution models,and then the accuracy and applicability of these approximate solutions are determined.Finally,a new failure criterion for determining the buckling of sandwich structure is established.The new criterion leads to better prediction precision and is concise,and is thus easy to be applied in engineering.