Effects of nonhomogeneity, cell damage and strain-rate on impact crushing of a strain-softening cellular chain

Summary The effects of a systematic spatial variation in properties (nonhomogeneity), cell damage and strain-rate on the gross deformation of a cellular system subjected to impact are examined via a one-dimensional model of masses interconnected by strain-softening structural links. Damage initiation, propagation and distribution in the mass-link chain and the deceleration imposed on the colliding body are studied. Results show that damaged cells decrease the energy absorption capacity while rate sensitivity exerts an opposing stabilizing influence by spatially distributing deformation more evenly and smoothing out fluctuations in the resisting force of the system. Variation in cell mass and compliance along the chain strongly affect damage patterns and promote localization of crushing in the vicinity of weaker cells. These findings have implications on cellular systems such as crushable polymeric foams.

[1]  V.P.W. Shim,et al.  Dynamic Crushing of Strain-Softening Cellular Structures—A One-Dimensional Analysis , 1990 .

[2]  Norio Sato,et al.  Mechanism of high energy absorption by foamed materials-foamed rigid polyurethane and foamed glass , 1984 .

[3]  S. R. Reid,et al.  RESPONSE OF ONE-DIMENSIONAL METAL RING SYSTEMS TO END IMPACT. , 1984 .

[4]  R. R. Cousins.  A theory for the impact behavior of rate‐dependent padding materials , 1976 .

[5]  M. Boyce,et al.  An experimental and anaiytical investigation of the large strain compressive and tensile response of glassy polymers , 1990 .

[6]  Michael F. Ashby,et al.  The mechanical properties of cellular solids , 1983 .

[7]  V.P.W. Shim,et al.  Dynamic crushing of a ductile cellular array , 1987 .

[8]  Michael F. Ashby,et al.  Deformation and energy absorption diagrams for cellular solids , 1984 .

[9]  S. J. Green,et al.  High-velocity deformation properties of polyurethane foams , 1969 .

[10]  V.P.W. Shim,et al.  Lateral crushing in tightly packed arrays of thin-walled metal tubes , 1986 .

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

[12]  J. Throne,et al.  Closed-Cell Foam Behavior Under Dynamic Loading-I. Stress-Strain Behavior of Low-Density Foams , 1984 .

[13]  N Jones,et al.  STRUCTURAL ASPECTS OF SHIP COLLISIONS , 1983 .

[14]  M. Richardson,et al.  Load-Deflection Analyses of Shock Mitigating Polyurethane–Silicone Foams , 1985, Cellular Polymers.

[15]  V.P.W. Shim,et al.  Microdynamics of Crushing in Cellular Solids , 1988 .

[16]  W. M. Hinckley,et al.  Analysis of rigid polyurethane foam as a shock mitigator , 1975 .