The optimization thickness of single/double composite patch on the stress intensity factor reduction

Abstract

The repairing process of structures using bonding of composite materials is an efficient and economic way of increasing service life of damaged structures. The finite element method is developed and applied to assist in the design, assessment and optimization of the proposed plans before they are implemented, therefore reducing cost and time. In this study, the finite element method is used to analyze the behavior of a repaired crack using single and double circular composite patches by determining the stress intensity factor reduction. The effects of geometrical and mechanical properties of the patch on the fracture parameters are highlighted. The results show that the thickness gain and the reduction of the asymptotic value of the SIF in the case of the double patch is 7% when compared to the single one. Thus, the gain in the thickness decreases when the thickness of the bonded patch increases up to a value eP = 0.8 mm and beyond this value, it starts increasing. However, an inverse behavior occurs for the mixed mode. In addition, whatever is the size of the strengthened crack, the gain in thickness exceeds 16% in mode I and 20% in mixed mode.

Effect of Bonded Composite Patch on the Stress Intensity Factors for a Center-Cracked Plate

“…Patch thickness represents one of the best means for improving patch repair performance. Thus, many researchers investigated the patch thickness effect on the repair performance in damaged structures [4,5,15]. Mhamdia et al [16] achieved almost 50% decrease in the crack tip SIF by increasing the patch thickness to repair a cracked plate under mechanical loading.…”

“…Using the same code, an investigation of composite patch use to repair a cracked plate was carried out. The effect of the thickness of the patch and adhesive were considered and the patch was designed with circular shape and implemented on an edge-cracked rectangular plate [4].…”

Digital Image Correlation Measurement of the Deformation and Failure in PBX Brazilian Discs Reinforced with CFRP Patches

“…The use of CFRP patches is an efficient and economic method for structural reinforcement. In addition to their excellent mechanical properties (e. g., high strength and stiffness), CFRP patches share multiple physical and chemical advantages (e. g., they are light weight, have great formability, and superior corrosion resistance); therefore, they are widely used in engineering fields, such as aerospace, automotive, and civil structures [22–28].…”

Influence of π overlaminates on the mechanical behavior of all-composite adhesively bonded π joints

“…To obtain accurate stresses, 3D finite element models were often used in the composite structure analysis. 27,28 The 3D finite element models of composite joints were established by implementing the geometry configuration, material properties, boundary conditions, initial load and load steps with software ABAQUS Õ . A typical finite element mesh is shown in Figure 2 for the typical joint.…”