B_4C增强铝基复合材料力学性能有限元模拟

Simulation of mechanical behaviors of B_4C reinforced Al matrix composites by finite element

建立了颗粒增强铝基复合材料的轴对称单胞模型,并通过有限元方法模拟了B_4C颗粒增强5083铝基复合材料的力学性能和微观应力分布。结果表明,模拟结果与实验结果吻合较好,模拟椭球体颗粒增强复合材料的抗拉强度为485 MPa,而实验值为477 MPa,相对误差仅为1.7%。颗粒形状对复合材料微观应力场有很大影响:圆柱体颗粒的尖角处容易造成应力集中,而球体颗粒界面处应力分布较为均匀。在一定范围内,复合材料的弹性模量和抗拉强度随着B_4C颗粒体积分数的增加而增加。在颗粒体积分数不变的情况下,不同长径比的颗粒沿复合材料受力方向定向排列时,颗粒的长径比越大,复合材料的弹性模量、强度等力学性能也越高。

An axisymmetric unit cell model of particle reinforced Al matrix composites was established,and the mechanical behaviors and micro-stress distribution of B4C particles reinforced Al5083 matrix composites were simulated by finite element method.The results show that the simulation result agrees well with the experimental result.The simulated tensile stress of spheroidicity particle reinforced composites is 485 MPa,while the experimental value is477 MPa,indicating a relative error as low as 1.7%.Particle shapes have a significant influence on the micro-stress field of composites：the sharp edge of cylindrical particle leads to a stress concentration easily,while the spherical particle results in a relatively uniform stress distribution at the interface.Elastic modulus as well as tensile strength of the composites increase with the increase of volume fraction for B4C particle in a certain range.In the case of constant particle volume fraction,when the particles with different aspect ratios are aligned along the load direction,the larger the aspect ratio of particles,the higher the elastic modulus and tensile strength of composites.