Experimental investigation and numerical analysis for concrete-CLT connections

The mechanical characteristics of concrete to cross laminated timber (CLT) connections plays an essential role in a hybrid structure. This study mainly deals with an experimental and numerical study on the load-slip behaviour of concrete-CLT connections under cyclic loading, where six specimens with two different loading types (i.e., parallel and perpendicular to the grain of CLT) were executed. The failure modes of all specimens were the bolts shear off at the location of the interface between concrete and CLT, associated with the cracking and splitting of CLT panels depending on loading directions. Then the numerical model whose nonlinearity is concentrated on the spring element is created. To calibrate the model parameters, the procedure of parameter estimation using unscented Kalman filter (UKF) is employed to identify the parameters of a hysteresis model. Two assessment methods, including the equivalent energy elastic-plastic curve assessment and an energy-based damage assessment, are used to comprehensively evaluate the estimated result. The model estimate is consistent with the experimental result, demonstrating the identified parameters having good accuracy. The calibrated parameters of a hysteresis model provide a good database when such type of connections are incorporated into a finite element model of a structural system. (C) 2019 Elsevier Ltd. All rights reserved.