The Bending Of Moderately Thick Rectangular Plates With Four Free Edges On The Elastic Foundation Of Two-Parameter

This thesis is sponsored by the National Natural Science Foundation which is assumed by Prof. Huang Yi. The paper puts forward bending theory of flat plate with extensive four-displacement and the governing differential equations are accurately derived from moderately thick rectangular plates with four free edges on the elastic foundation of two-parameter by means of variational method ,considering transverse extension and contraction displacement 3 for the first time,basing on Hu Haichang's bending theory of flat plate with extensive three-displacement.And the accurate boundary condition are derived.The number of boundry conditions is four because of the increased numbers of extensive displacements.The thesis sucessfully solve the bending problems of moderately thick rectangular plates with four free edges on the elastic foundation of two-parameter by means of solving the uncertainty coefficient in the trial functions which is solved from the governing differential equations by means of variational method after substituting the trail functions of the four extensive displacement into plate-foundation enery expressioaThe theory which is advanced by the paper can solve most problems with concertrated loads or stress concentration much better than Hu Haichang's theory and it can calculate the error of Hu's theory without concidering of the extensive displacement 3.The thesis puts forward bending theory of flat plate with extensive four-displacement for the first time,so it has significant theoretical significance.And the theory is helpful and practical for the design and construction of expressway,airport aircraft parking area,wharf freight shed and plate type foundation.