Moment-curvature diagrams for CLT panels accounting for orthogonal to grain compression timber properties

Typically, panel-to-panel and panel-to-foundation connection zones in Cross-Laminated Timber (CLT) walls consist of steel-to-timber mechanical connections (hold-downs and angle-brackets) and timber-to-timber contact. While hold-downs and angle brackets are extensively studied in literature, the role of timber-to timber contact is underestimated. The platform constructional technology used for build CLT walls requires that the vertical timber panels compresses the horizontal CLT floors, engaging the orthogonal to grain timber properties in the seismic response. This paper discusses a new development concerning a theoretical sectional model for CLT panels proposed by the authors in a recent work, where strength of the panels subjected to combined axial force and bending moment was studied accounting for orthogonal to grain timber properties. As advancement, a theoretical moment-curvature model for CLT panels is proposed in this paper and the displacement capacity (i.e., ductility) is investigated. The main parameters which affect the ductile behavior of the panels have been studied by means of parametric analyses, i.e. varying cross-section dimensions, amount of axial force, and hold-downs resistance. Theoretical results have been also compared with numerical ones derived from a bi-dimensional finite element model developed by the authors and a good matching between the results has been highlighted.