Browse > Article
http://dx.doi.org/10.5228/KSPP.2002.11.1.069

Determination of pressure-Dependent Yield . Criterion for Polymeric Foams  

김영민 (연세대학교 대학원 기계공학과)
강신일 (연세대학교 기계·전자공학부)
Publication Information
Transactions of Materials Processing / v.11, no.1, 2002 , pp. 69-74 More about this Journal
Abstract
In addition to lightweight and moldable characteristics, polymeric foams possess an excellent energy absorbing capability that can be utilize for a wide range of commercial applications, especially in the crashworthiness of the automobiles. The purpose of the present study is to develop experimental methodology to characterize the pressure dependent yield behavior of the energy absorbing polymeric foams. For the compression test in a triaxial stress sate, a specially designed device was placed in a hydraulic press to produce and control oil pressure. For the test material, the polyurethane foams of two different densities were used. The displacement of the specimen, the load subjected to the specimen, and oil pressure applied to the specimen were measured and controlled. Stress strain curves and yield stresses for the four different oil pressure were obtained. It was found from the present experiments that the polyurethane foams exhibited significant increases in yield stress with applied pressure or mean normal stress. Based on this observation, a yield criteria which included the effect of the stress invariant were established for the polymeric foams. The obtained experimental constants which constituted the pressure-dependent yield criterion were verified.
Keywords
Pressure-Dependent Yield Criterion; Polymeric Foams; Mean Normal Stress; Coulomb-Mohr Criterion;
Citations & Related Records
연도 인용수 순위
  • Reference
1 C.C. Chou, Y. Zhao, L. Chai, J. Co, and G.G. Lim, 1995, "Development of Foam Models as Applications to Vehicle Interior", SAE Technical Paper, No.952733.
2 L.W. Hu, and K.D. Pae, 1963, "Inclusion of the Hydrostatic Stress Component in Formulation of the Yield Condition", Journal of Franklin Institute, 275, p. 491.   DOI   ScienceOn
3 J. Zhang, Z. Lin, A. Wong, N. Kikuchi, V.C. Li, A.F. Yee, and G.S. Nusholtz, 1997, "Constitutive Modeling and Material Characterization of Polymeric Foams", Journal of Engineering Materials and Technolory, Vol. 119, p.284.   DOI   ScienceOn
4 J.A. Sauer, D.R. Mears, and K.D. Pae, 1970, "Effects of hydrostatic pressure on the mechanical behavior of polyetrafluoroethyene and polycarbonate", European Polymer Journal, Vol. 6, p. 1015.   DOI   ScienceOn
5 Fu S. Chang, Y. Song, D.X. Lu, and C.N. DeSilva, 1998, "Unified constitutive equations of foam materials", Journal of Engineering Materials and Technology, Vol. 120, p. 212.   DOI   ScienceOn
6 S.C. Sinha and J.O. Mitchell, 1994, "Constitutive modeling of energy absorbing foams", SAE Paper, No. 940880.
7 J.D. Rehkopf, G.W. Brodland, and G.M. M.cNeice, 1996, "Experimentally separating fluid and matrix contributions to polymeric foam behavior", Experimental Mechanics, p. 1.
8 L.J. Gibson, M.F. Ashby, J. Zhang, and T.C. Triantafillou, 1989, "Failure surfaces for cellular materials under multiaxial loads - I. Modelling", International Journal of Mechanical Science, Vol.31, No.9, p. 635.   DOI   ScienceOn