Full-Scale Test of a Two-Story Partial Frame Formed by Box-Type CLT Unit Connected With Large-Diameter Screws

This study presents an experimental and analytical study on the structural performance of a box-type CLT unit system with simplified connections using large-diameter screws. Element tests and full-scale cyclic loading tests of a two-story unit were first conducted, followed by the nonlinear frame analyses based on structural performance evaluation methods. The experiment results clarified the moment–rotation behavior of the joints, the transition of neutral axis position during deformation, and the formation of a stable bending resistance mechanism. Besides, analytical models reasonably captured initial stiffness and yielding behavior of the frame, while limitations in reproducing post-yield strength degradation were identified.