Reducing Weld Sizes in Circular Hollow Section Connections

减小圆形空心截面连接的焊缝尺寸

• 批准号: RGPIN-2019-04093
• 负责人: Tousignant, Kyle
• 金额: $ 2.26万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=749160
• 关键词: Reducing; Weld; Sizes; Circular; Hollow

In Canada, the cost of steel fabrication labour (for connections) can account for 60% of the cost of a steel structure. This % continues to rise. It is therefore increasingly important for engineers to reduce labour required to make connections to keep Canada's steel industry competitive. For welded tubular structures, this is a present challenge due to a lack of design guidance on welding to circular hollow sections (CHS). This is because the behaviour of welds in such joints, with respect to eccentric loading and non-uniform loading, is not well-understood. In lieu of guidance, designers "oversize" welds to prevent failure. This is usually a safe approach, but it leads to a lot of unnecessary labour for joint preparation and welding. The long-term objective of this research program is to develop a better (more economical, yet still safe) design approach for welds in CHS connections. First, this research will identify the effect of eccentric loading on the strength of two types of welds: fillet welds and partial joint penetration (PJP) groove welds. Lab tests will be conducted on weld-critical eccentrically tension-loaded cruciform connections (ETLCCs) with one-sided welds (to mimic the situation in CHS connections). The effect of weld type, root penetration, eccentricity (magnitude and direction), and plate-element thickness on weld strength will be identified. Then, post-rupture tests (e.g. Vickers hardness) will be used to characterize the local material properties of the ETLCCs near the welds (i.e. the properties of the filler metal, base metal, and heat-affected zone). These properties will subsequently be used in finite element (FE) models of the ETLCCs to study approaches to simulating weld fracture. A standardized approach for extending large-scale fracture-critical connection test results (using FE methods) will be developed. Lastly, with this new approach, FE models of CHS connections (with weld fracture) will be developed to determine the combined effect of non-uniform loading and eccentric loading on the weld strength. Large-scale, fracture-critical lab tests will be conducted, in parallel, to verify these models. This research will generate new knowledge and much-needed design guidance on welding to CHS that will help engineers reduce weld sizes and associated labour costs. It will also support the training of 2 doctoral, 3 master's and 2 undergraduate highly qualified personnel.

在加拿大，钢材制造劳动力(用于连接)的成本可以占到钢结构成本的60%。这个百分比还在继续上升。因此，工程师们越来越重要的是减少连接所需的劳动力，以保持加拿大钢铁行业的竞争力。对于焊接钢管结构，这是一个目前的挑战，因为缺乏关于焊接圆形空心截面(CHS)的设计指南。这是因为在偏心荷载和非均匀荷载作用下，此类接头中焊缝的行为还没有得到很好的理解。为了避免失败，设计者用“超大尺寸”的焊缝来代替指导。这通常是一种安全的方法，但它会导致大量不必要的接头准备和焊接劳动。这项研究计划的长期目标是开发一种更好的(更经济，但仍然安全)的CHS连接焊缝设计方法。首先，这项研究将确定偏心载荷对两种类型的焊缝强度的影响：角焊缝和部分接头熔透(PJP)坡口焊缝。实验室测试将在带有单面焊缝的焊接关键偏心受拉十字连接(ETLCC)上进行(以模拟CHS连接中的情况)。将确定焊缝类型、根部熔深、偏心(大小和方向)以及板件厚度对焊缝强度的影响。然后，将使用断裂后测试(例如维氏硬度)来表征焊缝附近ETLCC的局部材料性能(即填充金属、母材和热影响区的性能)。这些特性随后将用于ETLCC的有限元(FE)模型，以研究模拟焊接断裂的方法。将开发一种扩展大规模断裂关键连接试验结果的标准化方法(使用有限元方法)。最后，采用这种新的方法，建立了具有焊缝断裂的CHS节点的有限元模型，以确定非均匀载荷和偏心载荷对焊接强度的联合影响。同时，将进行大规模的、对骨折至关重要的实验室测试，以验证这些模型。这项研究将产生关于焊接到CHS的新知识和急需的设计指导，这将帮助工程师减少焊接尺寸和相关的劳动力成本。还将支持培养2名博士、3名硕士和2名本科生高素质人才。