材料期刊网

三维编织复合材料的性能预测对三维编织复合材料的性能设计有重要意义.在现有研究的基础上,针对三维四向编织复合材料力学性能预测,考虑了基体孔隙和加载方向对测量结果的影响,引人了系数c来描述孔隙的影响,提出修正后的刚度平均法,建立了新的有限元分析模型.采用修正过后的刚度平均法和新的有限元分析模型,将结果同力学实验结果进行对比,发现新的模型得到的结果与实验吻合得较好,且理论计算与有限元法得到的结果非常接近,可以用于预测三维四向编织复合材料的力学性能.同时采用修正后的刚度平均法,将新模型的结果同现有模型的结果进行对比,新模型的结果表明:(1)纵向弹性模量在编织角较大时存在一个谷值;(2)加载方向对横向弹性模量的测量结果有很大影响;(3)系数c较好地描述了孔隙对于材料力学性能的影响;(4)横向剪切模量并不在某个编织角存在峰值,而是随编织角的增大而增大.

Performance prediction of 3-D braided composites is of great significance to performance design.On the basis of other researchers' research about 3 dimension braided composites,with pore of matrix and load direction's effect on measure result considered,coefficient c was imported to describe the pore's effect on matrix's elasticity modules,inherent stiffness averaging method (SAM) was fixed,and a new finite-element analysis model was built.By comparing the data of SAM and FEM (finite element method) with experimental data,it's found that the new model fit experimental data well and the result of SAM are closed to the result of FEM.Thus it can be used to predict the mechanical property of 3 dimension braided composite.With fixed stiffness averaging method,the results of new model are compared to the current model.The results indicate that:(1) longitudinal modulus of elasticity reaches its nadir at specific braiding angle;(2) the load direction does affect the measuring result of transverse modulus of elasticity;(3) the import of coefficient c is reasonable;(4) transverse shear modules doesn't reach its peak value at specific braiding angle,it grows when braiding angle gets bigger.