The effect of slip stiffness on the behavior of timber-concrete composite slabs

Abstract Timber-concrete composite systems offer improved structural performance compared to bare cross-laminated timber slabs, but their effectiveness strongly depends on the stiffness of the shear connectors between both materials. This paper examines how varying the slip stiffness influences the mechanical response of the composite slabs. Three primary analytical models are compared against a two-layer finite element model. Parametric analyses reveal a critical range of connector stiffness, roughly between 10 4 and 10 6 kN m −1 m −2 , in which deflections are sensitive to changes in slip stiffness. Beyond this range, either full or minimal composite action is effectively reached. The study proposes a practical approach to selecting upper and lower thresholds for connection stiffness ( k max and k min ).