Dvisluoksnės sijos įtempių ir deformacijų būvis dėl temperatūrinių ir drėgminių deformacijų įvertinant sluoksnių praslydymą

Abstract

The stresss strain state analysis of two-ply beam with limited slip-capacity shear joint subjected to hygrotermal load taking into account layers slipping is presented in the current research. The main relations based on the theory of built up bars are obtained. Presented technique allows to determine the limits of variation of the layers strength, beam section properties and joint stiffness taking into consideration cracking of the layers. It have been established that increasing of joint stiffness leads asymptotical nearing of hygral and temperatute strain difference to values which can produce cracking of the beam even with absolutely stiff joints. The stress due to hygrothermal deformations in two layered concrete-timber, concrete-steel and concrete-concrete ply beams can be cause of the cracks in concrete layer as well as cause of increasing of beam displacements. Therefore the hygral and thermal strains of the layers must be taken into account in design practice.