A review of stress concentration studies on fibre composite panels with holes/cutouts

Abstract

Composite panels are widely used as structural members due to their high strength-to-weight ratio. In order to reduce further weight, cutouts or notches are introduced in these members. These cutouts also serve utility requirements such as man-holes for purpose of service as well as for passing electric or fuel lines. An aircraft wing rib is a typical example of such a composite panel. Even while composites with holes or cutouts provide great savings in weight compared to metallic structures, the presence of holes itself leads to strength reduction. The reduction in strength is due to the concentration of stress around the vicinity of the hole while the structure is under loading. Different-sized and shaped holes/cut-outs are used in composites structural members, which may serve for different purposes. They, in turn, introduce their own versions of stress concentrations effects in such members leading to weakening of the structure. The stress concentration effect in fibre composites also depends on other factors like fibre orientation, fibre material, matrix material, etc. Loading can also influence stress concentration. This review pursues vast research done in this area and attempts to compare and summarise the diverse findings for designers to obtain a comprehensive concept on stress concentration factor as an effective tool for composite structure design.

Influence of fiber surface treatment on the tribological properties of Calotropis gigantea plant fiber reinforced polymer composites

“…[46] It was noted that increase in test temperature from 200 to 350 C increased the CoF of composites initially and then decreased. [47][48][49] In the current experiment, CGFs were adopted to manufacture epoxy-based composites and tribological analysis was done. CGFs were used in untreated, NaOH, and KMnO 4 treated conditions and the effects of chemical treatment on rate of wear, frictional force, and CoF were determined.…”

Fatigue Life Improvement of Cracked Aluminum 6061-T6 Plates Repaired by Composite Patches

“…Traditional methods of repairing aluminum alloys, for instance, mechanical fastening, could lead to new defects. Composite patches, unlike traditional methods, do not cause any damage to the parent plate and can be replaced several times [ 1 , 2 , 3 , 4 , 5 , 6 ]. Fiber-reinforced polymer composites are the right choice for being used as a patch since these materials have a high stiffness-to-weight ratio, good fatigue resistance, and excellent corrosion resistance [ 7 , 8 , 9 , 10 ].…”

Buckling characteristics of cut-out borne composite stiffened hyperbolic paraboloid shell panel

“…Bash et al 53 reported buckling behavior of thin carbon/epoxy composite plates with rectangular cut-outs considering variation in position and number of cut-outs. The problem of stress and strain concentrations around cut-outs has been addressed by tailoring the panel in-plane stiffness by means of fiber-steered laminates, [54][55][56] cut-out reinforcement designs, 57 defense hole system, 58 etc.…”