偏心落锤冲击下钢筋混凝土梁的荷载路径重分布与损伤非对称性：耦合SPH-FEM研究

中文摘要 AI 辅助

目前评估冲击荷载下钢筋混凝土（RC）梁时，通常采用跨中冲击配置，但实际冲击可能偏离跨中，形成不等的剪切跨度。本研究采用经验证的耦合光滑粒子流体动力学-有限元法（SPH-FEM）模型，探究冲击偏心如何改变力传递与损伤发展：混凝土采用SPH粒子建模，钢筋、支座及冲击器采用FEM实体单元建模。在与跨中落锤试验验证后，将全跨偏心冲击案例与匹配的短跨参考案例对比：首次接触力峰值随偏心变化微小，但响应分布变化明显；最大偏心时，短跨剪切力达跨中冲击值的2.23倍，呈现剪切主导的重分布，单位长度吸收能量在短跨侧呈相同趋势，达长跨侧的4.29倍；匹配参考显示，全跨偏心梁的局部剪切力可比对称短跨梁高18.4kN；损伤场从对称跨中损伤转向短跨侧非对称损伤，低强度案例中破碎更明显。因此，偏心冲击应作为全跨剪切传递与损伤非对称问题评估。

英文摘要

Reinforced concrete (RC) beams under impact are commonly assessed using central-impact configurations, but practical impacts may deviate from midspan and create unequal shear spans. This study investigates how impact eccentricity changes force transfer and damage development using a validated coupled smoothed particle hydrodynamics--finite element method (SPH--FEM) model. Concrete is modeled with SPH particles, while reinforcement, supports, and the impactor are modeled with FEM solid elements. After validation against central drop-weight tests, full-span eccentric-impact cases are compared with matched short-span references. The first contact-force peak changes only slightly with eccentricity, whereas the response distribution changes clearly. At the largest eccentricity, shorter-span shear reaches up to 2.23 times the central-impact value, showing shear-dominated redistribution. Absorbed energy per unit length follows the same trend in shorter-span, reaching up to 4.29 times the longer-span-side value. Matched references show that full-span eccentric beams can develop up to 18.4 kN higher local shear than symmetric short-span beams. Damage fields shift from symmetric central damage to asymmetric shorter-span-side damage with clearer fragmentation in low-strength cases. Eccentric impact should therefore be evaluated as a full-span shear-transfer and damage-asymmetry problem.

补充信息

DOI

10.3390/app16136700