PSI - Issue 60

Anupoju Rajeev et al. / Procedia Structural Integrity 60 (2024) 222–232 Author name / Structural Integrity Procedia 00 (2019) 000–000

224

3

practical constraints, experimental investigation of extreme loads is challenging. Numerical simulations offer deeper insights into structural behavior. Jiang et al. [20] performed detailed FEM simulations of impact tests on RC beams. Proper material models are critical for simulation convergence. Agardh and Laine [21] and Banthia [22] developed finite element models for predicting deformation under shock and impact, while Aoude et al. [7] incorporated a concrete damage plasticity model in FE analysis, successfully capturing RCC beam behavior under static loads. Traditionally, structural design often assumes linear elastic behavior, overlooking the nonlinear plastic response of materials for simplicity. However, this approach can lead to overly conservative designs that may not be cost effective. Allowing structural elements to undergo controlled plastic deformations can better harness their energy absorbing capabilities when exposed to dynamic loads. Ductile design, which integrates plastic behavior and ensures adequate warning before ultimate collapse, is gaining traction in designing structural members for severe loading conditions. Therefore, it is crucial to account for plastic behavior in dynamic load analyses. Several analytical models have been proposed to assess the deflection of structural members subjected to high impulsive loads. One widely adopted approach is the single-degree-of-freedom (SDOF) approximation, which simplifies the member's behavior to a basic system with minimal computational complexity. In this study, we focus on the dynamic response of a reinforced concrete cantilever column subjected to shock loading. By modeling the column as an SDOF system and employing transformation factors, we derive an analytical solution for the column's maximum deformation. The Unified Facilities Criteria (UFC) [23] code utilizes SDOF approximations to model blast loading responses, idealizing the resistance function of the member as elastic and perfectly plastic. Determining the dynamical response of RC structures under dynamic loads can be challenging, especially for short interval loads. It is a multifaceted topic that requires a comprehensive understanding of material response, failure mechanisms, and design considerations. Accurate dynamic analysis is crucial for safeguarding structures against extreme loads, and this study aims to propose a framework for more reliable design charts by incorporating all relevant effects. This study aims to contribute to the understanding of dynamic load effects on reinforced concrete structures and the establishment of accurate design guidelines to ensure structural resilience in extreme conditions. Nomenclature Symbol Description Strain rate � Static yield strain of concrete in compression �,��� Limiting strain in concrete in compression � � � Modified yield strain of concrete in compression � �� Elastic strain of concrete in compression � �� Plastic strain of concrete in compression � �� Inelastic strain of concrete in compression � Static yield strain of concrete in tension �� Dynamic yield strain of concrete in tension � �� Elastic strain of concrete in tension � �� Plastic strain of concrete in tension � �� Inelastic strain of concrete in tension � Peak static compressive strength of concrete � Peak static tensile strength of concrete �� compressive strength under bi-axial loading �� compressive strength under uniaxial loading