大跨度钢桁架屋盖现场焊接拼接节点加固设计与监测分析

发布时间：2018-03-27 16:08

本文选题：焊接拼接节点　切入点：焊缝　出处：《合肥工业大学》2017年硕士论文

【摘要】：大跨度钢桁架常采用工厂分段制作、现场焊接拼接的方法进行施工安装。存在拼接焊缝的钢桁架往往因现场焊接质量达不到要求成为钢结构的薄弱环节,使结构的安全性、适用性和耐久性得不到保证。合肥某工程的屋顶采用大跨度钢结构屋盖体系,由5榀主桁架和11榀次桁架组成。由于钢桁架现场拼接焊接施工质量不合格,直接影响结构承载能力和结构安全性,迫使结构在中途进入停工状态。在进行续建之前需要对原有钢结构部分进行加固,排除隐患。本文以合肥某工程大跨度钢桁架屋盖结构施工过程中的加固、监测项目为工程背景,对钢桁架焊接缺陷加固技术进行研究。针对工程检测发现的杆件拼接焊接严重质量缺陷,考虑构件受力特点,结合现场施工环境,采用在H型钢构件左右两侧外边缘平行于腹板对称焊接钢板,通过增加焊缝,改变截面形式对焊接拼接节点进行加固。为了验证加固设计的有效性,对构件焊接拼接节点处的受力性能进行了数值模拟分析。进一步研究了一般受力状态下缺陷构件加固前后的受力特性,通过改变相关参数如焊缝缺陷长度、加固拼接板尺寸、构件加载形式等,分析这些参数对拼接板加固现场焊接拼接节点构件受力性能的影响效果及规律。为保证结构的安全,提高加固质量,与有限元分析形成对比,在施工过程中对结构进行了施工控制和节点应力、位移状态监测。通过对比分析数值模拟结果与钢桁架梁焊接拼接节点处应变实测结果,验证了钢桁架梁采用腹板补强增大截面法进行焊接拼接节点加固的传力有效性。论文分析结果可为其他类似的钢结构工程的加固设计提供参考。
[Abstract]:The long span steel truss is often made in factory sections, and the method of spot welding splicing is used to construct and install the steel truss. The steel truss with spliced weld seam often becomes the weak link of the steel structure because the welding quality is not up to the requirement, which makes the structure safe. The applicability and durability are not guaranteed. The roof of a certain project in Hefei is made up of 5 main trusses and 11 secondary trusses. The roof of a certain project in Hefei is composed of 5 main trusses and 11 secondary trusses. It directly affects the bearing capacity of the structure and the safety of the structure, forcing the structure to enter a stoppage state in the middle of the way. Before the continuation of the construction, the original steel structure should be strengthened. In this paper, the reinforcement and monitoring project of large-span steel truss roof structure in Hefei project is taken as the engineering background. The welding defect reinforcement technology of steel truss is studied. In view of the serious quality defects of bar joint welding found by engineering inspection, considering the mechanical characteristics of the members, combined with the field construction environment, In order to verify the effectiveness of the reinforcement design, the welded joints are strengthened by adding weld seam and changing the section form by using symmetrical welded steel plate parallel to the web plate on the left and right sides of the H-section steel member, in order to verify the effectiveness of the reinforcement design. Numerical simulation analysis of the mechanical behavior of welded joints is carried out, and the mechanical characteristics of defective members before and after reinforcement are further studied. By changing the relevant parameters such as the length of weld defects, the size of the strengthened splicing plate is obtained. In order to ensure the safety of the structure and improve the strengthening quality, the effect of these parameters on the mechanical behavior of the welded joint members strengthened by the splicing plate is analyzed. In the course of construction, the structure is controlled and the stress and displacement of the joints are monitored. The results of numerical simulation are compared with the measured results of the welded joints of steel truss beams. This paper verifies the validity of the reinforcement of welded joints by using the method of web reinforcement and increasing section. The results of this paper can be used as a reference for the reinforcement design of other similar steel structures.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU393.3;TU758.11

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