Vacuum forming of thermoplastic foam

The process of thermoforming of foam sheet is analyzed using both finite element modeling and experiments. A simple constitutive model for finite tensile deformations of closed cellular material around its glass transition temperature is proposed, starting from well-known results from Gibson and Ashby (1988). The model is implemented in a finite element code and applied in isothermal vacuum forming simulations. The distributions of thickness and in plane strains are in adequate accordance to the experimental results.

[1]  R. Marissen,et al.  On the Linear Elastic Properties of Regular and Random Open-Cell Foam Models , 1997 .

[2]  R. Flumerfelt,et al.  Prediction of cellular structure in free expansion polymer foam processing , 1996 .

[3]  D. Weaire,et al.  The modeling of liquid and solid foams , 1995 .

[4]  Matthew J. Silva,et al.  The effects of non-periodic microstructure on the elastic properties of two-dimensional cellular solids , 1995 .

[5]  N. Suh,et al.  The viscoelastic behavior of microcellular plastics with varying cell size , 1995 .

[6]  R. D. Krieg,et al.  A constitutive theory for rigid polyurethane foam , 1995 .

[7]  C. Snowden,et al.  Pt and Zn based ohmic contacts to p-type InP , 1994, Proceedings of 1994 IEEE 6th International Conference on Indium Phosphide and Related Materials (IPRM).

[8]  P. T. Vreede.  A finite element method for simulation of 3-dimensional sheet metal forming , 1992 .

[9]  W. E. Warren,et al.  The Nonlinear Elastic Behavior of Open-Cell Foams , 1991 .

[10]  D. J. Green,et al.  The effect of cell size on the mechanical behavior of cellular materials , 1990 .

[11]  M. Boyce,et al.  Large inelastic deformation of glassy polymers. part I: rate dependent constitutive model , 1988 .

[12]  L. Gibson,et al.  Anisotropy of foams , 1988 .

[13]  W. E. Warren,et al.  The Linear Elastic Properties of Open-Cell Foams , 1988 .

[14]  M. Ashby,et al.  The mechanics of three-dimensional cellular materials , 1982, Proceedings of the Royal Society of London. A. Mathematical and Physical Sciences.

[15]  G. Menges,et al.  Estimation of mechanical properties for rigid polyurethane foams , 1975 .

[16]  S. V. Kanakkanatt.  Mechanical Anisotropy of Open-Cell Foams , 1973 .

[17]  Masao Nakamura,et al.  Mechanical Properties of Plastic Foams , 1969 .

[18]  M. C. Shaw,et al.  The plastic behavior of cellular materials , 1966 .

[19]  W. Ko.  Deformations of Foamed Elastomers , 1965 .

[20]  Alan N. Gent,et al.  Mechanics of Foamed Elastic Materials , 1963 .

[21]  B. D. Carleer,et al.  Finite element analysis of deep drawing , 1997 .

[22]  Roderic S. Lakes,et al.  Relating the Properties of Foam to the Properties of the Solid from Which it is Made , 1994, Cellular Polymers.

[23]  A. Lagzdin',et al.  Single-bar model of cellular materials subjected to large elastic deformations , 1992 .

[24]  E. Clutton,et al.  Structure-property relationships in thermoplastic foams , 1991 .

[25]  Michael F. Ashby,et al.  Failure surfaces for cellular materials under multiaxial loads—II. Comparison of models with experiment , 1989 .

[26]  Michael F. Ashby,et al.  Failure surfaces for cellular materials under multiaxial loads—I.Modelling , 1989 .

[27]  Richard M. Christensen,et al.  Mechanics of low density materials , 1986 .

[28]  J. Throne.  Polystyrene Foam Sheet Expansion During Heating , 1986 .

[29]  Alan N. Gent,et al.  The deformation of foamed elastic materials , 1959 .