Preloaded bolted connections made of stainless steel under fatigue loading in civil engineering structures

土木工程结构疲劳载荷下不锈钢预载螺栓连接

• 批准号: 521501197
• 负责人: Professorin Dr.-Ing. Natalie Stranghöner
• 金额: --
• 依托单位: Institut für Metall- und Leichtbau
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/521501197?language=en
• 关键词: Preloaded; bolted; connections; made; stainless

In the construction industry, structures and bolted connections made of stainless steel are increasingly being used as load-bearing components in steel construction, e.g. in bridge structures, roadway crossings and coastal protection systems, due to their excellent corrosion resistance in aggressive environments. While in the past mainly austenitic stainless steel was used, in recent years austenitic-ferritic stainless (duplex) steel has also been increasingly used. However, preloaded bolted connections made of stainless steel in fatigue-loaded structures have so far not been considered feasible due to ignorance of the expected preload losses as a result of the viscoplastic deformation behaviour of the components as well as fears regarding cold welding effects. For these reasons, the project does not only focus on the fatigue loading capacity, but also considers the principle tightening behaviour of the boltin assemblies including tightening parameters in order to prevent premature failure of the bolts. As further aspects, the viscoplastic deformation behaviour, the interfacial pressure of the clamping package to avoid plastic deformations and thus ultimately too high preload losses are considered. The central research objective of this application is thus the development of concepts for describing and recording the load- and structure-dependent non-linear behaviour of preloaded bolted connections made of metal construction bolting assemblies made of austenitic stainless and duplex steel in the typical diameter range M12 to M36 under fatigue loading for use in the construction industry. Ultimately, the aim is to transfer these findings into boundary conditions for an optimised bolting assembly type made of stainless steel for use in the construction industry. To achieve the research objectives, an extensive programme of experiments on the aspects mentioned is planned, which will be extended by numerical FE parameter studies with FE models validated on the experiments. Finally, an analytical model for describing the viscoplastic deformation behaviour is to be developed, interfacial pressures for clamping packages made of stainless austenitic and duplex steel for use in the construction industry are to be derived, the tightening behaviour of prestressed bolted joints as a basis for developing suitable criteria for describing the requirements for minimum ductility, The fatigue strength of stainless steel bolts under tensile and shear loads will be determined and boundary conditions for an optimised type of bolting assemblies for preloading for use in civil engineering will be developed on the basis of the results obtained.

在建筑行业，不锈钢结构和螺栓连接越来越多地用作钢结构的承重部件，例如钢结构。由于其在恶劣环境中具有出色的耐腐蚀性，因此可用于桥梁结构、道路交叉口和海岸防护系统。虽然过去主要使用奥氏体不锈钢，但近年来奥氏体-铁素体不锈钢（双相）钢的使用也越来越多。然而，由于忽视了部件粘塑性变形行为导致的预期预紧力损失以及对冷焊效应的担忧，迄今为止，在疲劳加载结构中由不锈钢制成的预紧螺栓连接尚未被认为是可行的。由于这些原因，该项目不仅关注疲劳承载能力，还考虑了螺栓组件的原则拧紧行为，包括拧紧参数，以防止螺栓过早失效。作为进一步的方面，考虑粘塑性变形行为、避免塑性变形的夹紧组件的界面压力以及因此最终过高的预载损失。因此，该应用的中心研究目标是开发概念，用于描述和记录典型直径范围内由奥氏体不锈钢和双相钢制成的金属结构螺栓组件制成的预载螺栓连接的负载和结构相关非线性行为用于建筑行业的疲劳载荷下的 M12 至 M36。最终，目的是将这些发现转化为边界条件，以优化建筑行业使用的不锈钢螺栓组件类型。为了实现研究目标，计划对上述方面进行广泛的实验计划，并将通过数值有限元参数研究以及经实验验证的有限元模型来扩展该计划。最后，将开发一个用于描述粘塑性变形行为的分析模型，导出用于建筑行业的由不锈钢奥氏体和双相钢制成的夹紧组件的界面压力，预应力螺栓接头的紧固行为作为基础制定适当的标准来描述最小延展性的要求，将确定不锈钢螺栓在拉伸和剪切载荷下的疲劳强度，并将开发土木工程中用于预载的优化类型螺栓组件的边界条件所得结果的基础。