CAJ | 학술논문

研究了聚氨酯弹性体材料在压缩变形时的率相关特性.根据不同压缩应变率下的响应特性,确定了材料的瞬态响应,利用多步松弛试验确定了材料平衡响应.通过瞬态响应和平衡响应研究材料瞬态模量和平衡模量之间的关系,发现随压缩应变其变化趋势是一致的,可利用最小二乘法确定两者的差值.用五项Mooney-Rivlin应变能函数分别对材料的瞬态响应和平衡响应建模,用Prony级数所表示的松弛函数建立线性粘弹模型.通过瞬态响应、平衡响应和单步松弛确定材料的松弛强度和松弛时间.将非线性超弹模型和线性粘弹模型相结合,建立了聚氨酯弹性体材料的非线性粘弹本构模型.通过对所建模型的数值解与试验结果的比较,证明所建立的非线性粘弹本构模型能很好地描述聚氨酯弹性体材料在压缩时的力学特性.
연구료취안지탄성체재료재압축변형시적솔상관특성.근거불동압축응변솔하적향응특성,학정료재료적순태향응,이용다보송이시험학정료재료평형향응.통과순태향응화평형향응연구재료순태모량화평형모량지간적관계,발현수압축응변기변화추세시일치적,가이용최소이승법학정량자적차치.용오항Mooney-Rivlin응변능함수분별대재료적순태향응화평형향응건모,용Prony급수소표시적송이함수건립선성점탄모형.통과순태향응、평형향응화단보송이학정재료적송이강도화송이시간.장비선성초탄모형화선성점탄모형상결합,건립료취안지탄성체재료적비선성점탄본구모형.통과대소건모형적수치해여시험결과적비교,증명소건립적비선성점탄본구모형능흔호지묘술취안지탄성체재료재압축시적역학특성.
The rate-dependence characteristics of polyurethane elastomer were investigated by compression tests.The instantaneous response and equilibrium response of the material which represents responses of infinitely fast loading and infinitely slow loading were determined through different strain-rate compression tests and multi-step-relaxation test respectively.The relation between instantaneous modulus and equilibrium modulus was studied and it is found that they are coincidently varied with compression strain,the least-square method was used to determine the difference.Five-term Mooney-Rivlin strain energy function was used to modeling instantaneous response and equilibrium response,and Prony series was employed as material relaxation function to describe linear viscoelasticity.Nonlinear viscoelasticity constituent model was founded by combined nonlinear hyperelasticity and linear viscoelasticity model. Numerical results obtained from nonlinear viscoelasticity constituent model are compared with the test results to verify the adequacy of the proposed model.