预制裂纹参数及相对密度对平面多孔结构裂纹扩展的影响

Influences of prefabricated crack parameters and relative density on crack propagation in planar cellular structures

基于有限元仿真和准静态三点弯曲实验研究了预制裂纹参数和相对密度对平面多孔结构板裂纹扩展的影响规律。考虑预制裂纹尺寸、数量、倾角和位置以及多孔结构板的相对密度,共设计9组模型;利用有限元仿真软件获得模型弹塑性阶段的应力图及载荷-位移曲线并进行分析,提出相应规律;同时采用3D打印机熔融丝制备多孔结构模型,利用微机控制电子万能试验机完成三点弯曲实验,并与有限元仿真结果进行拟合分析,验证结论的正确性。结果表明:预制裂纹的尺寸越大、数量越多,则模型抑制裂纹萌生和扩展的能力越强;多孔结构的相对密度对不同的单元形状及单元取向模型抑制裂纹萌生及扩展的影响不同。

Based on finite element simulation and quasi-static three-point bending experiments,the influences of prefabricated crack parameters and relative density on crack propagation of planar cellular structures were studied.Considering the size,number,angle and position of the prefabricated cracks and the relative density of the cellular structure plate,a total of nine groups of models were designed.The stress diagram and load-displacement curve of the elastic-plastic phase of the model were obtained and analyzed by finite element simulation software to reveal the corresponding mechanisms.At the same time,a 3D printer melt wire was used to prepare the cellular structure model.And a microcomputer control electronic universal testing machine was used to complete the three-point bending experiment.The fitting analysis was carried out with the finite element simulation results to verify the correctness of the conclusion.The results show that the larger the size and number of prefabricated cracks there are,the stronger the ability of the model there is to inhibit crack initiation and propagation.The relative density of the cellular structure has different effects on the inhibition of crack initiation and propagation with different element shapes and element orientation models.