Effect of infilled CLT shear walls on the lateral performance of glued-laminated timber frames: Experimental and numerical analysis

Abstract

A new timber structural system about the combination of cross-laminated timber (CLT) and glued-laminated timber (GLT) aiming to improve the timber lateral performance and satisfy the seismic demands has recently been proposed, highlighting the important influence on the design of timber frame-shear walls structure. This paper presents the lateral behaviour and seismic performance of GLT frame infilled with CLT shear walls by experimental and finite element numerical analysis. Four specimens of 1:1.5 scale including one bare GLT frame and three GLT frames infilled with CLT shear walls were designed to research the lateral performance under the cyclic loading tests. The mechanical characteristics of these specimens were effectively evaluated in the form of theoretical derivation under the lateral load, and the theoretical models of the beam-column joint and the column-base joint were established. Based on the theoretical calculation methods, the finite element models of four specimens were established and analyzed by Abaqus software to research the lateral performance of the influence of CLT shear walls on the GLT frame. The results indicate that the lateral deformation of the bare GLT frame is obvious, the shear cracks emerge in the joints, and the damage degree of the beam end of the beam-column joint is significantly greater than that of the column-base joint. The lateral load-bearing capacity of the GLT frame is improved after being infilled with CLT shear walls, and the damage degree of GLT frame joints is significantly improved. The elastic lateral stiffness of GLT frame infilled CLT shear walls with the opening can reach 9.66–13.1 times higher than that of bare GLT frame according to the test results. From the beginning of loading to the failure stage, the lateral load of specimens provided by the CLT shear wall is more than 50 %, and the contribution of the CLT shear wall to the lateral performance of the structure is significant in collaborative work. The numerical analysis based on the FE models of GLT frame infilled with CLT shear wall shows that the opening type, size and thickness height ratio of the CLT wall are obvious effects on the lateral resistance of the structure. The lateral load-bearing capacity increase by about 95.06–127.5 % when the thickness of the CLT shear wall of three-layers wood panels increases from 30 mm to 105 mm. The lateral resistance increases by 49.29–72.29 %, and the lateral stiffness increases by 48.26 % when the thickness of the CLT shear wall of five-layers wood panels increases from 50 mm to 150 mm. The research shows that CLT can increase the lateral load-bearing capacity and stiffness of structures, which can satisfy the demands of better lateral performance and sustainable buildings with a low carbon cycle.