|
Title |
Evaluation of Punching Shear Strength According to Diagonal Crack Angle Variation at the Interface of Slabs with PC Head Using Nonlinear Finite Element Analysis
|
|
Authors |
조성원(Seong-Won Cho) ; 이문석(Moon-Seok Lee) ; 손동희(Dong-Hee Son) ; 배백일(Baek-Il Bae) ; 최창식(Chang-Sik Choi) |
|
DOI |
https://doi.org/10.4334/JKCI.2026.38.1.031 |
|
Keywords |
무량판 구조; 뚫림전단강도; 전단균열각; 비선형 유한요소해석 flat plate slab; punching shear strength; diagonal crack angle; nonlinear finite element analysis |
|
Abstract |
Flat-plate structures without beams are vulnerable to punching shear due to stress concentrations at slab?column connections. Current design codes assume a constant 45° crack angle and uniform concrete, which may not accurately capture the behavior of slabs with high-strength precast concrete (PC) near the column. This study evaluates punching shear strength by considering crack angle variation at the PC?cast-in-place (CIP) interface using a nonlinear finite element model validated against experimental data. Parametric analyses varied the compressive strength, PC head width, and flexural reinforcement ratio, revealing increased punching shear strength with all parameters. Observed crack angles ranged from 16° to 50°, deviating from the 45° assumption. Comparisons with ACI 318-19 and KDS 14 20 indicate that these codes may misestimate strength under composite slab behavior. The study consequently highlights the need to redefine the critical section to account for material discontinuity and PC head geometry, providing a basis for improved design of hybrid flat-plate systems.
|