Lee Jeonghwa, Kim Seungjun, Lee Keesei, Kang Young Jong
Future and Fusion Laboratory of Architectural, Civil and Environmental Engineering, Korea University, Seoul 02841, Korea.
School of Civil, Environmental and Architectural Engineering, Korea University, Seoul 02841, Korea.
Materials (Basel). 2021 Apr 22;14(9):2130. doi: 10.3390/ma14092130.
To enhance structural performance of concrete and reduce its self-weight, ultra-high-performance concrete (UHPC) with superior structural performance has been developed. As UHPC members with 180 MPa or above of the compressive strength can be designed, a rational assessment of thin-walled UHPC structural member may be required to prevent unexpected buckling failure that has not been considered while designing conventional concrete members. In this study, theoretical local buckling behavior of the thin-walled UHPC flanges was investigated using geometrical and material nonlinear analysis with imperfections (GMNIA). For the failure criteria of UHPC, a concrete damaged plasticity (CDP) model was applied to the analysis. Additionally, an elastic-perfectly plastic material model for steel materials was considered as a reference to establish differences in local buckling behavior between the UHPC and steel flanges. Finite element approaches were compared and verified based on test data in the literature. Finally, this study offers several important findings on theoretical local buckling and local bending behavior of UHPC flanges. The inelastic local buckling behavior of UHPC flanges was mainly affected by crack propagation due to its low tensile strength. Based on this study, possibility of the local buckling of UHPC flanges was discussed.
为提高混凝土的结构性能并减轻其自重，已开发出具有卓越结构性能的超高性能混凝土（UHPC）。由于可以设计抗压强度在180MPa及以上的UHPC构件，因此可能需要对薄壁UHPC结构构件进行合理评估，以防止在设计传统混凝土构件时未考虑到的意外屈曲破坏。在本研究中，采用考虑初始缺陷的几何和材料非线性分析（GMNIA）对薄壁UHPC翼缘的理论局部屈曲行为进行了研究。对于UHPC的破坏准则，在分析中应用了混凝土损伤塑性（CDP）模型。此外，将钢材的理想弹塑性材料模型作为参考，以确定UHPC翼缘和钢翼缘在局部屈曲行为上的差异。基于文献中的试验数据对有限元方法进行了比较和验证。最后，本研究给出了关于UHPC翼缘理论局部屈曲和局部弯曲行为的若干重要发现。UHPC翼缘的非弹性局部屈曲行为主要受其低抗拉强度导致的裂缝扩展影响。基于本研究，讨论了UHPC翼缘发生局部屈曲的可能性。
