多铁性层状复合材料中平行界面上的多裂纹问题

发布时间：2018-01-12 16:31

本文关键词：多铁性层状复合材料中平行界面上的多裂纹问题　出处：《内燃机与配件》2016年11期 　论文类型：期刊论文

【摘要】：与压电/压磁颗粒复合材料相比,压电/压磁层状复合材料结构简单,而且常温下的磁电耦合系数较大,因而具有更大的应用前景。然而,在力电磁载荷的作用下,压磁层和压电层的界面难免会发生开裂。这是因为:第一,夹杂、空穴等制造缺陷一般集中在界面区域;第二,长时间工作之后,压电/压磁复合材料界面处的导电银胶可能发生老化,在载荷作用下,老化的界面易于产生损伤甚至开裂;第三,界面两侧压磁层与压电层的材料性能失配往往会导致界面附近区域产生应力集中,从而引起界面开裂。因此,各层间界面上的裂纹问题也十分值得研究。该类复合材料一般是由多层压电相与压磁相交替粘接而成,为了简化起见,本文仅研究由中间的压磁层和两侧的压电层所组成的三层复合材料中两个平行界面上的多裂纹问题。现有文献在对压电/压磁层状复合材料开展断裂力学分析时,一般都不计压电层的导磁性与压磁层的介电性。然而,实际上它们却往往未必可以忽略。因此,在本文的分析中,我们假定压电层的磁导率与压磁层的介电系数同时都不为零。在此基础上,本文对压电/压磁层状复合材料的界面非等长多裂纹问题进行理论推导和数值计算,探讨几何参数和物理参数对界面断裂规律的影响,为工程中的界面防断裂设计提供理论参考。
[Abstract]:Compared with piezoelectric / piezomagnetic particle composites, piezoelectric / piezomagnetic laminated composites have a simpler structure and larger magnetoelectric coupling coefficient at room temperature, so they have more application prospects. Under the action of the force and electromagnetic load, the interface of the pressure layer and the piezoelectric layer will inevitably crack. This is because: first, the manufacturing defects such as inclusions and holes are generally concentrated in the interface area; Secondly, after working for a long time, the conductive silver colloid at the interface of piezoelectric / piezomagnetic composite may be aged. Under the action of load, the aging interface is prone to damage and even crack. Thirdly, the mismatch of the properties of the piezoelectric layer and the magnetic layer on both sides of the interface often leads to the stress concentration near the interface, which leads to the crack of the interface. The crack problem at the interlayer interface is also worth studying. This kind of composite material is composed of the piezoelectric phase and the piezomagnetic phase, which are bonded alternately, for the sake of simplification. In this paper, we only study the problem of multiple cracks at two parallel interfaces in a three-layer composite composed of a middle piezomagnetic layer and a piezoelectric layer on both sides. In the present literature, the fracture mechanics analysis of piezoelectric / piezomagnetic laminated composite is carried out. . Generally, the conductance magnetism of piezoelectric layer and the dielectric property of piezoelectric layer are not considered. However, in fact, they are not always negligible. Therefore, in the analysis of this paper. We assume that the permeability of the piezoelectric layer and the dielectric coefficient of the piezoelectric layer are not zero at the same time. On the basis of this, the non-equal-length multi-crack problem at the interface of the piezoelectric / piezomagnetic laminated composite is derived theoretically and numerically. The influence of geometric and physical parameters on the fracture law of interface is discussed, which provides a theoretical reference for the design of anti-fracture interface in engineering.
【作者单位】：装甲兵工程学院;
【分类号】：TB33;O346.1
【正文快照】： 1理论模型假设材料沿z轴极化,则它在xoy平面内具有各向同性性质。如图1所示,该层状复合材料处于xoy平面内的均匀电场E0(或磁场H0)之中,外加电场E0(或磁场H0)的方向垂直于材料的上、下表面;另外,为了对比起见,分别给出了材料上、下表面受到两种不同机械约束的情况:一种是位移约

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