Theoretical approaches for bending analysis of founded Euler–Bernoulli cracked beams

Abstract

The purpose of the present study is to investigate the static behavior of cracked Euler–Bernoulli beams resting on an elastic foundation through implementing analytical, approximate and numerical approaches. Among common approximate and numerical approaches, Galerkin’s and the finite element methods, respectively, are selected to solve the governing equations. The crack-caused imperfection is simulated by two discrete spring models whose stiffness factors are determined in terms of the stress intensity factor and the geometric parameters. In the analytical solution, a Dirac’s delta function is used to define the singularity in the flexural stiffness and to derive an improved governing equation. In the Galerkin solution, two deflection functions corresponding to the right- and left-hand sides of the crack point are offered to satisfy the governing equation. In the finite element method by introducing a novel technique, a modified stiffness matrix whose components are enriched by material and geometric parameters of the crack is proposed. This study focuses on the effect of various parameters including the crack depth and position, boundary conditions, elastic foundation as well as the discrete spring models on the beam deflection through aforementioned theoretical approaches. Lastly, results from these three theoretical solutions are verified through comparison with each other and Abaqus software.