Modelling of multilayer actuator layers by homogenisation technique using Digimat software

This paper is concerned with the microstructure of adhesive joints composed of BaTiO₃ ceramic material and two kinds of adhesives, with a special emphasis on the numerical modelling of grain size, shape and material porosity. BaTiO₃ powder for use in stacked-disk multilayer actuator production is manufactured using the solid-state technique. The properties of BaTiO₃ material at each stage of its fabrication that influence its application for the stacked-disk multilayer actuator are presented and discussed. The parameters characterising the properties of the fabricated pellets are also described. Implicit time-discretisation and consistent tangent operators are employed. A 3D microstructure model of BaTiO₃ using Digimat-FE software is generated. Then, effective elastic constants of BaTiO₃ and epoxy adhesive composites are calculated by numerical simulation. The Mori-Tanaka homogenisation scheme for representative volume elements of BaTiO₃ and epoxy adhesives composites is carried out using Digimat-MF software in order to obtain failure characteristics of the composite material.     

3D microstructure-based modelling of the deformation behaviour of ceramic matrix composites

In this paper the experimental and numerical investigations of microstructure modelling of multilayer actuator are considered. BaTiO₃ powder is manufactured using the solid-state technique. The main parameter influencing the possibility of application of BaTiO₃ ceramics on actuators is the grain size of the sintered materials. Three kinds of pellets with different average grain sizes were considered. The adhesive joints of a BaTiO₃ and Ag-based conducting electric current epoxy adhesive were used to fabricate the model of actuator. A 3D microstructure model of BaTiO₃ and composites were generated using Digimat-FE software. The Mori–Tanaka and double inclusion homogenization models for representative volume elements of multilayer actuator were carried out using Digimat-MF software, in order to obtain the failure characteristics of the composite material. To investigate the failure of the ceramic matrix composite the Hashin-Rotem criterion was used.     

基于Digimat RVE的碳纤维增强聚丙烯复合材料性能分析

采用Digimat软件包对造纸/热压模塑法制备的碳纤维增强聚丙烯（CF/PP）复合材料建立等效体积单元（RVE）,研究了碳纤维含量、碳纤维长径比和基体中碳纤维取向对CF/PP复合材料力学性能、导热性能和导电性能的影响。模拟实验结果表明,碳纤维含量从5 wt%增至30 wt%,CF/PP复合材料弹性模量和电导率分别提高290%和750%;碳纤维长径比从100提高至700,CF/PP复合材料电导率提高了约54倍;碳纤维取向张量的变化对CF/PP复合材料RVE的弹性模量和导热系数的影响可以忽略不计。Digimat软件对CF/PP复合材料导热系数的模拟值较精确,在100℃下测量的导热系数实验结果与软件模拟结果误差为0.48%。