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，钢结构制造劳动力（用于连接）的成本可占钢结构成本的 60%。这个百分比还在继续上升。因此，对于工程师来说，减少连接所需的劳动力以保持加拿大钢铁行业的竞争力变得越来越重要。对于焊接管状结构来说，由于缺乏圆形空心型材 (CHS) 焊接的设计指南，这是目前的挑战。这是因为此类接头中的焊缝在偏心载荷和不均匀载荷方面的行为尚不清楚。设计师用“加大”焊缝来代替指导，以防止出现故障。这通常是一种安全的方法，但会导致接头准备和焊接方面产生大量不必要的劳动力。该研究计划的长期目标是为 CHS 连接中的焊缝开发更好（更经济但仍然安全）的设计方法。首先，本研究将确定偏心载荷对两种类型焊缝强度的影响：角焊缝和部分焊透（PJP）坡口焊缝。实验室测试将在具有单侧焊缝的焊接关键偏心拉伸加载十字形连接 (ETLCC) 上进行（以模拟 CHS 连接的情况）。将确定焊缝类型、根部熔深、偏心率（大小和方向）和板单元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、母材金属和热影响区的性能）。这些属性随后将用于 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测试结果（使用有限元方法）的标准化方法。最后，通过这种新方法，将开发 CHS 连接（具有焊缝断裂）的有限元模型，以确定非均匀载荷和偏心载荷对焊缝强度的综合影响。将同时进行大规模的断裂关键实验室测试，以验证这些模型。 这项研究将产生有关 CHS 焊接的新知识和急需的设计指南，这将帮助工程师减少焊接尺寸和相关的劳动力成本。支持培养博士2名、硕士3名、本科高素质人才2名。