• Journal of Ocean Engineering and Technology
• /
• v.23 no.6
• /
• pp.124-130
• /
• 2009

This study presents a finite element simulation of elastic waves for detecting anti-symmetric damages in an adhesively-bonded single lap joint. Plane strain elements were used for modeling adherents (aluminum) and adhesives (epoxy). Three types of damage were introduced: thickness reduction, elasticity deterioration, and voids in the adhesive layers, and two excitation and reception arrangements (ER1 and ER2) were used to investigate the detectability of the damage. The simulation showed that symmetrically located damage, such as a thickness reduction, can be detected by one excitation and one reception arrangement (ER1) and anti-symmetric damages, such as elasticity deterioration and voids, can be detected by modified two-point elastic wave excitation (ER2). Compared with the ER1 arrangement, the ER2 arrangement does not require a baseline signal for damage detection; hence, an efficient method of anti-symmetric damage detection in an adhesively-bonded single lap joint is proposed.

• Journal of Ocean Engineering and Technology
• /
• v.24 no.1
• /
• pp.172-177
• /
• 2010

This study presents an explicit dynamic analysis of an adhesively bonded single-lap joint under an impact load. The finite element software, ANSYS LS-DYNA, was used for the analysis and Von Mises stresses were obtained from the analysis. To model the adherents, solid elements were used and a rigid body was assumed for impactor modeling. Three impact heights (1 m, 5 m, and 10 m) were applied to consider different impact conditions and infinite boundary conditions were applied to the end-area of each adherent to save computational time in the analysis. In addition to investigating the stresses in the normal state, we also investigated the stresses in a damaged state (elasticity deterioration), simulated by a change in Young's modulus for 36 of the 3600 elements in the upper layer of the adhesive. The results showed that the location of damage is critical to the stress state of each layer (upper, middle, and lower).

• Composites Research
• /
• v.31 no.1
• /
• pp.17-22
• /
• 2018

Long Fiber Prepreg Sheet (LFPS) has the advantages of excellent production efficiency and formability for complex shapes compared to conventional continuous fiber reinforced composites. When fibrous composites are used with different materials, joining method is important because strength of the joining part determines the strength of the hybrid structure. In this study, the adhesive joint strengths of co-cured LFPS and aluminum were evaluated under various surface treatment conditions and environmental conditions (temperature and moisture conditions). Mechanical abrasion and plasma exposure were used for the surface treatment. The adhesive joints experienced various surface treatments were tested by using single lap joint specimens. Adhesive strengths under various conditions were compared and the most appropriate condition was determined.