Furniture Design Ideas

In order to predict the strength of composite scarf joints, finite element based computer models are developed and assessed against the experimental data. Fracture mechanics based models are selected to predict the joint strength. A small size of crack is assumed at the critical location of the joint interface. The critical location is found using […]

Scarf joints are fabricated using carbon-fiber and fibreglass plain weave composites. Carbon – fiber is T700 while fibreglass is E-glass. The Derakane 510A ester resin is used as the binding matrix material. The scarf joint specimens are fabricated using the VARTM technique. After the base plate is fabricated using VARTM, it is cured for 72 […]

Young W. Kwon Naval Postgraduate School USA 1. Introduction In recent years, large composite structures have been used increasingly in the aerospace and naval industries. Such a large composite structure is mostly fabricated using the scarf joining technique so that multiple substructures can be connected together. Figure 1 shows three commonly used scarf joint configuration. […]

The main purpose of this study has been the determination of the effectiveness of bonded composite patches to repair cracked thin aluminum panels. The repair is realized by patching only one side of the panel in order to reduce the associated costs and time required. In most of the cases, in fact, the other side […]

1.3 Testing procedure In order to verify the effectiveness of analytical and numerical analyses some experimental measurements, for the damaged and repaired panels, are carried out. The tests are performed at room temperature in a 100 kN Metrocom Engineering SpA servo-hydraulic test machine. The tests are focused to evaluate the fatigue life of the structures […]

1.2 Analytical procedure Rose’s analytical model (Rose, 1981 and 1982) is used to compute the SIF for the repaired plates by single patch, Kr=Y- <r0/Vk (12) where Y is a geometric factor, which accounts for repairs to center or edge cracks; Y=1 for a repair to a centre crack; oo is the nominal stress that […]

The fatigue-crack growth prediction models usually employ the following Paris power law due to its simplicity (Pook, 2000). In this work, Paris law is used to study the fatigue behaviors of cracked plates: Ц = C(AK)m (7) The so-called material constants, C and m, for 6061-T6 aluminum alloy, are C=1.8404 10-9, m=2.3. The quantity AK […]

A finite element analysis of the configuration in Fig.1 is carried out, using the finite element code Franc2D/L developed at Kansas University (Swenson & James, 1998). The plate, without patch, was meshed using standard six node-isoparametric elements with triangular shape, as showed in Fig.2. These elements perform well for elastic analysis and have the advantage […]

1.1 Analytical procedure In the present analysis, the Irwin – Westergaard model (Pook, 2000) is used to calculate SIF in the panels without patch. The basic relationships are herein reported. The linear elastic fracture mechanics (LEFM) for a plate of infinite size and central crack (opening mode I) is given by the following expression: The […]

The geometry of the cracked structure in the present work is shown in Fig. 1. It was considered a 6061-T6 aluminum alloy plate; a through thickness crack is used to simulate the defect in the structural components. The fracture is made with the technique of Electrical Discharge Machining (EDM), based on the erosion of metals […]