Design approach for cost-effective hybrid CLT floors

There is a growing research and production interest for the application of lower-cost hybrid cross-laminated timber (CLT) panels composed of timber layers of dissimilar quality. Therefore, an approach for the design of cost-effective hybrid CLT panels in bending, based on the existing analytical and novel finite element procedures, is presented in the paper. The gamma-method, the extended gamma method, and the composite theory are applied in the analysis of square panels, while the finite element model based on the Reddy’s full layerwise theory is used for the complex-shape panels in bending. An extensive benchmark technical and economic study is performed for 25 CLT panels, considering various spans, lamination schemes, geometries, and boundary conditions. Cost savings made by using a lower timber class in central zones of CLT panels are highlighted and quantified. This concept shows an economic potential that should be considered during the design and production of CLT panels in structural engineering applications, such as lightweight floor structures.