Collaborative Research: Shear-Buckling Mechanics for Enhanced Performance of Thin Plates

薄钢板常用作建筑、桥梁、塔楼、飞机等结构构件，由于其细长，在剪切荷载作用下易发生屈曲，从而限制其承载能力。最近的研究表明，许多现有的模型并不能代表极限剪切屈曲的真实力学。该项目将研究和推进剪切屈曲响应的知识，从而提高使用薄板的结构的经济性、耐久性和安全性。这项研究的重点是钢板，但它为其他材料，如铝和复合材料奠定了基础，可以在未来的工作中考虑。该项目还解决了美国土木工程师学会(ASCE)最近发布的重大挑战：(A)到2025年，显著提高基础设施项目在其生命周期中的绩效和价值，以及(B)促进社会基础设施投资的优化。其结果将通过减少材料使用量来提高成本效益；通过增加极限剪切强度来增强坚固性；通过增加屈曲承载能力来减少屈曲的发生并提高对意外载荷的弹性(例如，需要更少的维修)。该项目的总体目标是全面研究钢板的剪切屈曲行为，从而产生(A)新的预测模型，以捕捉真实的力学行为，以及(B)设计改进，以提高经济性、健壮性和生命周期性能。研究计划包括非线性有限元研究和实验测试。从弹性屈曲阶段到极限后屈曲能力的应力模式和载荷重分布的详细检查将是主要焦点。物理测试将探索新的面板配置，并将基于有限元力学研究确定潜在的材料优化。将利用利哈伊大学的设施进行试验，以检验钢板梁试件在有弯矩和无弯矩情况下的剪切屈曲性能。这些测试的数据将用于直接验证计算建模方法。

Thin steel plates are commonly used as structural elements in buildings, bridges, towers, aircrafts, etc. Due to their slenderness, these plates are susceptible to buckling under shear loading, thus limiting their capacity. The recent research shows that many existing models do not represent the true mechanics of ultimate shear buckling. This project will investigate and advance the knowledge of shear buckling response, thus leading to improved economy, durability, and safety of structures that use thin plates. The focus of this study is on steel plates, but it lays the foundation for other materials such as aluminum and composites that can be considered in future work. This project also addresses the grand challenges recently issued by the American Society of Civil Engineers (ASCE): (a) significantly enhance the performance and value of infrastructure projects over their life cycles by 2025, and (b) foster the optimization of infrastructure investments for society. The results will increase cost efficiency via decreased material usage; enhance robustness via increased ultimate shear strength; and reduce occurrence of buckling and increased resilience to unexpected loads (e.g. with fewer required repairs) via increased buckling load capacity. The overall objective of this project is to comprehensively investigate the mechanics of shear buckling behavior in steel plates, thus leading to (a) new predictive models that capture the true mechanics, and (b) design modifications that increase economy, robustness, and life-cycle performance. The research plan involves both nonlinear finite element studies and experimental tests. A detailed examination of the stress patterns and load redistribution from the elastic buckling stage to the ultimate postbuckling capacity will be the primary focus. Physical tests will explore new panel configurations, and potential material optimizations will be identified based on finite element mechanics studies. Experiments will be conducted using facilities at Lehigh University to examine the shear buckling performance of steel plate girder specimens, both with and without bending moment. The data from these tests will be used to directly validate the computational modeling approaches.