The Study On The Interfacial Mechanics-electrics Coupling And Time-dependence

With the development of materials science, the advanced materials such ascomposites, function materials, bonded and welded materials have increasinglyextensive application in engineering field. These materials all include the interface asa rule. The interface has an important influence on the total properties and behaviorsof the combination of materials or structures. The interface can transfer the loadinformation and keeps the integrity of the total structures in the same time. Inconsequence, building a reasonable interfacial mechanical model, is an importantsection in analyzing and assessing the combination materials or structures. As thecohesive zone model has built, it has increasingly applied to the study of interface.The traditional cohesive zone model only takes the information of mechanics fieldinto account, without consideration of the interfacial mechanics-electrics coupling andtime-dependence for the piezoelectric materials and the adhesive structures.The characteristics of the mechanics-electrics coupling in the piezoelectricmaterials makes the interface in piezoelectric materials or structures have thecharacteristics of the mechanics-electrics coupling. The traditional cohesive zonemodel cannot modeling the interface. A novel mechanics-electrics interfacial model,which includes the mechanical quantities and electrical quantities at the same time, ispresented in this paper. This novel interfacial model can describe the behavior ofmechanics-electrics coupling well. It can be applied to analyze the material propertiesand mechanics behaviors of the piezoelectric materials and structures include theinterface. The paper applies the mechanics-electrics interfacial model to simulate thepiezoelectric fiber push-out test and the piezoelectric composite, and demonstrate theavailability of this model.The interfacial adhesive mechanics of the adhesive structures is great complexity,which shows both the characteristics of elastic body and viscous fluid. Among therelevant conditions, the two most important are the time and temperature. Thetraditional cohesive zone model only applies to describe the static problems withoutconsideration of the time effect. In this paper, the time effect is introduced byparalleling the Maxwell model and the Needleman cohesive zone model, and the four parameters time-dependent interfacial model in the condition of simple tension. Theinterfacial model is applied to analyze the metal adhesive structure in the condition ofsimple tension. It can be proved that the interfacial property has a certain influence onthe global mechanics behaviors of structures comparing the results with that in theperfect adhesion.