The Study On Mechanical Properties Of Shape Memory Polymer Foam Core Panel

In recent years,various kinds of sandwich structures have been widely used in many fields.And sandwich structures with shape memory effect have gained more and more attention.Compared with traditional sandwich structures,shape memory sandwich structures not only have good mechanical properties,but also the unique shape memory effect makes it have a broad application prospect in the field of self-repairing structure field,as well as in aerospace,civil engineering,navigation and other related fields.So far,studies on shape memory sandwich structure are relatively few.In this work,emphases are focused on the study of its basic mechanical properties and shape memory effect of shape memory sandwich structure.Firstly,shape memory epoxy/polyurethane foam used for the core of sandwich structure was fabricated by chemical process.And carbon fiber reinforced shape memory epoxy laminated plates were employed as outer layer of the sandwich structure.Put the two together,then shape memory sandwich structures were obtained.Then compression and viscoelastic property of shape memory epoxy/polyurethane foam were carried out.Combined with the experimental data,three-parameter-solid model was employed to fit the curves of relaxation experiment.Through analysis and calculation for foam compression behavior,elastic modulus during its elastic stage was obtained,as well as the law of modulus changing with temperature.The tensile and three-point bending tests for carbon fiber reinforced shape memory epoxy laminate were conducted in this work.From its related experimental curves,the bending modulus and bending strength are obtained by analysis.Furthermore,bending behavior of the sandwich structure was studied.Compared with the experimental results and bending equivalent theory results of sandwich beam,change rule of mechanical behavior with temperature was studied.And the cause of error is analyzed.Besides,it was carried out that the study for shape memory effect of shape memory epoxy/polyurethane foam and carbon fiber reinforced shape memory epoxy laminated plates.And tests for properties of recovery rate and fixation rate were also preceded,as well as its shape recovery process under condition of thermal drive.