Collaborative Research: Micromechanics-based Framework for Modeling Fracture of Weldments in Structural Steel

合作研究：基于微观力学的结构钢焊件断裂建模框架

基本信息

批准号：
2129445
负责人：
Amit Kanvinde
金额：
$ 24.51万
依托单位：
University of California-Davis
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-11-01 至 2024-10-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2129445&HistoricalAwards=false
关键词：
Collaborative Research Micromechanics based Framework

项目摘要

Civil infrastructure constructed from steel relies heavily on welding to connect various parts (such as beams and columns) to each other. Welded connections are often the weak points in these structures and are prone to fracture, leading to catastrophic failure or collapse under loads such as during earthquakes. Predicting and simulating such fracture are essential for safety assessment and design of these structures. However, this type of failure is challenging to simulate in computer models, because current methods cannot properly represent the changes in material properties caused by welding processes and how these changes weaken the structure. This award will support fundamental research to understand how welding changes material properties over very small dimensions in these connections, and then will create a method to use these properties within computer simulations to predict the failure of welded connections. The findings and software technology from this research will enhance the safety and resilience of buildings and other infrastructure, benefiting the nation’s society and economy. The involvement of underrepresented groups, education of students with new knowledge, and technology transfer to practitioners will result in broad impacts. This award will contribute to the National Science Foundation role in the National Earthquake Hazards Reduction Program (NEHRP). Welded steel connections often fail under extreme loads due to the complex and multiple microstructures that are formed in weldments, and the steep stress and strain gradients that interact with these microstructures. Current methods for simulating weldments cannot simulate the mechanical properties of these microstructures or their interactions with applied loads. This is especially true when these connections are subjected to large-scale yielding or Ultra Low Cycle Fatigue fracture (which occur commonly under extreme loads such as earthquakes). This research will develop fundamental understanding of weld microstructures and their mechanical properties through laboratory experiments on thermomechanically generated samples. Then, the research will upscale these findings to the structural scale through an innovative framework of multi-scale simulation. This knowledge and framework will be implemented for convenient integration within various numerical platforms (open source as well as commercial) that are popular with researchers and structural engineers. This approach (including its implementation) will be informed and validated by extensive laboratory testing and finite element simulation, and broadly disseminated to target audiences and user groups. Data generated by this research will be archived in the Natural Hazards Engineering Research Infrastructure (NHERI) Data Depot (https://www.DesignSafe-ci.org).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

民用基础设施依赖于焊接的焊接（例如其他部件）互相焊接。在地震期间，失败在计算机模型中都充满挑战，因为目前无法正确地，由Lding过程引起的INGESS材料的变化以及Sukes Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will The The The The Inder Inder Inder Inder Inder Inder Inder Inder Inder Inder Inder Inder Inders The The Inder Inders will Will Will Will Will Will Will Will Will Will Will Will Will Will Will Will在计算机模拟中预测焊接的方法。贡献国家减少地震计划（NEHRP）的作用，这是由于与微观结构相互作用的微观结构而在极端载荷下。大规模的疲劳疲劳（通常是在极端载荷下发生的）框架将在各种数值平台内实施，是流行的withrchers和结构工程师。。