دانلود Elastic and Viscoelastic Foundation Models

Abstract

The  present  paper  contains  a  critical  study  of  a  number  of foundation models  as  well  as a further development  of  some  of  the  ideas  involved. Among others  it  is  shown  that  the Pasternak  foundation is  a  mechanical model for the so-called  " generalized" foundation. It  is  also  demonstrated that  the  kernel  for the  Pasternak foundation in  plane  stress  or plane strain is  identical with Wieghardt's exponential kernel, and  that for the  three-dimensional case  the  kernel is  a  modified Bessel  function. It  is  also  shown that  the "nonsolvability" of  the problem  of  a  finite  beam  or  plate  resting  on  a  continuous foundation  as  posed by Wiegliardt and  further elaborated  by  Pflanz is  not  correct, and  that problems  of  this  type  are  solvable for  any  load  distribution permissible in  classical plate theory. Throughout  the paper,  emphasis is  placed  on  the proper  mathematical formulation  of  the physical problems  in  question.