3rd International Conference on Concrete and Steel Technology, Engineering and Design CASTED 2022 Virtual Conference May 19- 21, 2022
USING FRACTAL DIMENSIONS AS MATERIAL STRENGTH REDUCTION PARAMETER IN NONLINEAR ANALYSIS OF LIGHTLY REINFORCED
CONCRETE WALLS WITH CRACKS
Pher Errol B. Quinay – [email protected]
Institute of Civil Engineering, University of the Philippines Diliman
ABSTRACT
In line with the approach of incorporating pre-existing damage in nonlinear analysis of concrete structures through material strength reductions, we propose the Fractal Dimension based Reduction Approach (FDRA) that considers the fractal dimensions of observed crack patterns in modifying material strengths.
The methodology involves a coupled discretization of the crack map and numerical model of the structure, fractal dimension computations of crack pattern per element, and strength reductions based on an assumed exponential relationship between concrete material properties and the obtained fractal dimensions. Limited to plane stress elements and total strain based smeared crack models, the FDRA is initially verified with theoretical results from a classical finite element analysis. The FDRA is then validated with a reference experiment on two large scale, low aspect, low reinforcement ratio (0.0067 & 0.01) concrete shear walls.
Through the evaluation of force displacement relationships, the FDRA has been demonstrated to result in close agreement with considered numerical and experimental references.
Figures: (Left) Crack map; (Center) Finite Element model; and (Right) Force-displacement hysteresis curves (FDRA and Experiment)
About the Author(s)
Pher Errol B. Quinay is Associate Professor and the Head of the Structural Engineering Group in the Institute of Civil Engineering University of the Philippines Diliman. He holds the Beatriz Basa-Altura Professorial Chair in Civil Engineering. He obtained his Bachelor of Science in Civil Engineering degree from the University of the Philippines Diliman, Master of Engineering degree from the Tokyo Institute of Technology, and Doctor of Engineering degree from The University of Tokyo. His research interest is on computational mechanics related to structural and earthquake engineering. Link to profile page: https://pages.upd.edu.ph/pbquinay/
The co-authors of this paper are Mr. Joseph Lawrence G. Celeste (UPD-ICE) with email ([email protected]) and Engr. Karlo Daniel Q. Colegio (UPD-ICE) with email ([email protected]).
