Numerial Simulation And Experimental Study On Creep Properties Of EPE Cushioning Materials

EPE will experience the effects of static pressure,vibration and impact in storage,transportation and loading and unloading,especially the creep deformation caused by long-term static pressure has a significant impact on the bearing capacity,which reduces the buffer performance of EPE,so it is of great significance to study its creep mechanical properties.In this paper,the compressive creep behavior of EPE is deeply studied by conventional creep test,accelerated creep test and simulation.The long-term compressive creep behavior of EPE is analyzed according to creep model,EPE is accelerated by creep acceleration principle,and EPE is simulated by finite element software ABAQUS.By fitting the linear part of the stress-strain curve obtained by static compression experiment,the elastic modulus of EPE was obtained for the definition of finite element material properties.Through dynamic impact experiments,the maximum acceleration-static stress curves at different drop heights and weights were measured.The lowest point of the curve was obtained by fitting the hook function.Finally,3.3 k Pa,4.3 k Pa and 5.3 k Pa were selected as the stress variables of creep test.In this paper,the short-term compression creep test of EPE is carried out,and the main curve is formed by displacement in horizontal coordinate system.Three sets of main creep curves based on time-temperature equivalence principle and time-stress equivalence principle were compared with the actual creep curves.The results show that the average error between the main creep curve based on the time-temperature equivalence principle and the actual test is less than 10%within the time range of 0～10~6s,and the error gradually increases after 10~6s.Within the time range of 0～10~6s,the average error between the main creep curve based on time-stress equivalence principle and the actual test is less than 10%,and the creep acceleration principle can accurately predict the long-term creep behavior within a certain range.Based on Burgers constitutive model,the compression creep test was simulated by using finite element ABAQUS,and the simulation curve was compared with the test and accelerated characterization curve.The results show that the maximum error between the simulation and experiment is 5%,and the simulation model can accurately simulate the compression creep test.Within 10~6s,the results of the three are basically consistent.After10~6s,the accelerated characterization curve gradually deviates from the simulation and experimental curves,which may be caused by a small number of experiments or failure to consider the aging factor.