Knowledge of the relationship between stress and strain in polyethylene foam is indispensable to design the products in which polyethylene foam is used. However, few studies have been made on this relationship.
In this paper, a simulation model was assumed with consideration of the buckling, the property of gas and so on, in order to express the relationship between stress and strain in the process of compressing. Then, compressive tests were performed to verify this model. The main results obtained are as follows.
(1) The present model could express the relationship between stress and strain as evidenced by the results of compressive tests under the condition of a constant speed.
(2) The relationship between the shape of stress-strain curve and three parameters of this model, that is young's modulus E
, dispersion of buckling load α and buckling load β, became clear.
(3) The relationship between density and each parameter of E
, α and β could be approximated by simple equations.
(4) This model could explain the reason why the values of parameters E
, α and β are changed by the preceding loading condition.
(5) The relationship between cushioning properties and parameters became clear by the method of static evaluation.