The connections ensure lateral and shear resistance in CLT buildings, facilitating crucial interactions between walls and floors. CLT connectors are widely used at present and take strength as the control index, but they have poor energy dissipation performance and are not suitable for middle- and high-rise buildings in earthquake-prone zones. This study proposes a modified version of an existing energy dissipative hold-down connection that rectifies its flaws by incorporating innovative design and material solutions. An experimental study is conducted with quasi-static monotonic and reversed cyclic loading tests to investigate modified hold-down connection failure mechanisms and mechanical properties. Notable failure modes included steel rib ruptures and debonding between rubber and steel plate, with steel rib rupture as a dominant failure mechanism. Despite such failures, the connection maintained functionality, attributed to the effective bonding between the rubber and the steel bracket. The load-displacement curves of the hold-down exhibit a bi-linear pattern with the yielding point caused by the yielding of steel ribs. Almost all the specimens were classified as highly ductile, with ductility values exceeding 9.0 and an equivalent viscous damping ratio between 10 % and 18 %, indicating significant ductility and energy-dissipative capabilities. Furthermore, a simplified FEM model of the modified hold-down is established using ABAQUS software and validated against the experimental results. In addition, a parametric study was conducted to investigate the influences of modified design parameters on the mechanical properties and failure modes. The results of the comparison between the test and FEM model show the robustness of the proposed model in estimating the initial stiffness, post-yield stiffness, and yield force. Ultimately, the modified energy dissipation hold-down effectively rectifies former design flaws over its previous version, resulting in significantly improved performance, high energy dissipation capacity, and ductility by mitigating the brittle failures. This study provides a technical solution for future research to enhance the seismic resilience of modern high-rise CLT buildings through the real-world implementation of this type of modified hold-down connections.

中文翻译：

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改进型 CLT 结构耗能压具力学性能的实验和数值研究


这些连接确保了 CLT 建筑的横向和抗剪性能，促进墙壁和地板之间的重要相互作用。 CLT连接件目前应用广泛，以强度为控制指标，但其耗能性能较差，不适合地震多发区的中高层建筑。这项研究提出了现有耗能固定连接的修改版本，通过结合创新设计和材料解决方案来纠正其缺陷。通过准静态单调和反向循环加载测试进行了实验研究，以研究改进的压紧连接失效机制和机械性能。值得注意的失效模式包括钢肋断裂以及橡胶与钢板之间的脱粘，其中钢肋断裂是主要的失效机制。尽管存在此类故障，由于橡胶和钢支架之间的有效粘合，连接仍保持功能。压具的载荷-位移曲线呈现双线性模式，屈服点由钢肋的屈服引起。几乎所有样本都被归类为高延展性，延展性值超过 9.0，等效粘性阻尼比在 10% 至 18% 之间，表明具有显着的延展性和耗能能力。此外，使用 ABAQUS 软件建立了改进压紧装置的简化 FEM 模型，并根据实验结果进行了验证。此外，还进行了参数研究，以研究修改后的设计参数对机械性能和失效模式的影响。 试验与有限元模型的比较结果表明，该模型在估计初始刚度、屈服后刚度和屈服力方面具有鲁棒性。最终，改进的能量耗散抑制器有效地纠正了之前版本的设计缺陷，通过减少脆性故障，显着提高了性能、高能量耗散能力和延展性。这项研究为未来的研究提供了一个技术解决方案，通过在现实世界中实施这种改进的固定连接来增强现代高层 CLT 建筑的抗震能力。