Mechanism research of slip effect between frictional laminated beams

Jintu Zhong,Jie Wu,Quansheng Yan,Zhuojie Zhang

doi:10.1177/1687814019828461

Abstract

For laminated beams connected by Coulomb friction, interlayer slippage occurs when interfacial shear stress exceeds the resistant friction stress. Then, the physical properties of the laminated beams will change and may even cause structural damage. In this article, the law of interlayer slippage of laminated beams is obtained by mechanical derivation, and the finite element model is used for comparison verification. First, the internal shear force calculation formula of the laminated beam considering the interlaminar friction is derived from the segment micro-element method. Second, interlayer slippage laws of the frictional laminated beams in both horizontal and longitudinal direction are derived according to the hierarchical slip determination conditions. Third, according to the state quantity of different boundary conditions, the transfer matrix method is used to solve the longitudinal length of interlayer slip. Then, the design of the algorithm program is completed by MATLAB. Finally, based on the comparison between the finite element model calculation results and the calculation results of the algorithm program, the accuracy of the proposed method is verified. The analysis results indicate that slippage destroys the integrity of the laminated beam section and reduces the bending moment of inertia of the slip section of the beam. The influence of slip effect on the frictional laminated beams should be considered in deflection calculation.

Highlights

For bridge structures, the main part is the beam
This article provides a mechanical analysis of the interlayer slippage in the contact layer of the frictional laminated beam based on the section analysis method
A new algorithm for calculating the slippage effect of laminated beam is proposed based on the incremental iterative recursive method and transfer matrix method (TMM)

Summary

Introduction

The main part is the beam. The beam can be considered as a laminated structure with myriad of fine fiber layers. When the laminated beam is subjected to forces as a whole structure without interlayer slippage, the shear stress distribution of the segment is uniform. The shear stress tÃb of the bottom laminated beam segment at a y* distance from the neutral axis can be deduced, as shown in equation (10). Ð23Þ where IkÀall is a sum of the moment of inertia of all beam segments to their own independent neutral axis at kth slippage state It can be calculated by equation (24). The relationship between the state vectors at both ends of the beam element can be expressed as a matrix form with the transform matrix vl ul

EI l sin

Conclusion

Future work