{"title":"Experimental and numerical study on the long-term rotational deformation behavior of post-tensioned timber joints under sustained gravity loads","authors":"Xiuzhi Zheng, Minjuan He, Frank Lam, Zheng Li","doi":"10.1007/s43452-024-01096-0","DOIUrl":null,"url":null,"abstract":"<div><p>Long-term beam deflection is a key index during the serviceability limit state (SLS) design of timber beams under gravity loads. To accurately calculate the long-term beam deflection, it is necessary to reasonably capture the long-term rotational deformation of beam–column joints. However, the long-term rotational deformation of timber beam–column joints is still not fully understood, especially for post-tensioned timber (PTT) joints. In this study, long-term experiment was conducted over 930 days to investigate the time-dependent rotational deformation for PTT joints under variable environment and sustained gravity loads. Different gravity loading levels and connection details were considered. Time-dependent variations of key parameters including environmental conditions, moisture content, joint rotations, prestressing forces and strain deformation were captured. Based on observed data, a numerical approach about the long-term rotational deformation for PTT joints was developed and verified. Finally, the verified numerical approach was adopted for predicting the long-term joint rotation over a 50-year service life. This study demonstrated that the long-term rotation for post-tensioned timber joints globally increased over time and increased as the gravity loading level increased. Additionally, the long-term rotational deformation can be effectively reduced by steel reinforcement.</p></div>","PeriodicalId":55474,"journal":{"name":"Archives of Civil and Mechanical Engineering","volume":"25 1","pages":""},"PeriodicalIF":4.4000,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Archives of Civil and Mechanical Engineering","FirstCategoryId":"5","ListUrlMain":"https://link.springer.com/article/10.1007/s43452-024-01096-0","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}
引用次数: 0
Abstract
Long-term beam deflection is a key index during the serviceability limit state (SLS) design of timber beams under gravity loads. To accurately calculate the long-term beam deflection, it is necessary to reasonably capture the long-term rotational deformation of beam–column joints. However, the long-term rotational deformation of timber beam–column joints is still not fully understood, especially for post-tensioned timber (PTT) joints. In this study, long-term experiment was conducted over 930 days to investigate the time-dependent rotational deformation for PTT joints under variable environment and sustained gravity loads. Different gravity loading levels and connection details were considered. Time-dependent variations of key parameters including environmental conditions, moisture content, joint rotations, prestressing forces and strain deformation were captured. Based on observed data, a numerical approach about the long-term rotational deformation for PTT joints was developed and verified. Finally, the verified numerical approach was adopted for predicting the long-term joint rotation over a 50-year service life. This study demonstrated that the long-term rotation for post-tensioned timber joints globally increased over time and increased as the gravity loading level increased. Additionally, the long-term rotational deformation can be effectively reduced by steel reinforcement.
梁的长期挠度是重力荷载作用下木梁使用极限状态(SLS)设计中的一个关键指标。要准确计算梁的长期挠度,就必须合理捕捉梁柱连接处的长期旋转变形。然而,人们对木材梁柱连接处的长期旋转变形仍不完全了解,尤其是对后张法木材(PTT)连接处。本研究进行了为期 930 天的长期实验,以研究 PTT 接头在不同环境和持续重力荷载下随时间变化的旋转变形。实验考虑了不同的重力荷载水平和连接细节。研究捕捉了关键参数随时间的变化,包括环境条件、含水量、接头旋转、预应力和应变变形。根据观测数据,开发并验证了 PTT 接头长期旋转变形的数值方法。最后,采用经过验证的数值方法预测了 50 年使用寿命内的长期接头旋转情况。该研究表明,后张法木材接头的长期旋转随时间的推移而增加,并且随着重力荷载水平的增加而增加。此外,钢筋可有效减少长期旋转变形。
期刊介绍:
Archives of Civil and Mechanical Engineering (ACME) publishes both theoretical and experimental original research articles which explore or exploit new ideas and techniques in three main areas: structural engineering, mechanics of materials and materials science.
The aim of the journal is to advance science related to structural engineering focusing on structures, machines and mechanical systems. The journal also promotes advancement in the area of mechanics of materials, by publishing most recent findings in elasticity, plasticity, rheology, fatigue and fracture mechanics.
The third area the journal is concentrating on is materials science, with emphasis on metals, composites, etc., their structures and properties as well as methods of evaluation.
In addition to research papers, the Editorial Board welcomes state-of-the-art reviews on specialized topics. All such articles have to be sent to the Editor-in-Chief before submission for pre-submission review process. Only articles approved by the Editor-in-Chief in pre-submission process can be submitted to the journal for further processing. Approval in pre-submission stage doesn''t guarantee acceptance for publication as all papers are subject to a regular referee procedure.