Analysis of automotive mixed‐adhesive joints weakened by moist conditions: Experimental characterization and numerical simulation using cohesive zone model

Abstract

This paper is mostly concerned with an experimental and numerical study to clarify the behaviour and failure in the mono‐adhesive joints and mixed‐adhesive joints under different environmental conditions (dry [E0], 75.3% relative humidity [E1], 84.2% relative humidity [E2], and submerged in tap water [E3] at 25°C) and different strain rates (1 and 100 mm/min). Experimental investigations are compared with the numerical analysis, which is carried out by bilinear cohesive zone model (CZM). Through this work, degradations of cohesive parameters are calculated by using open‐faced double cantilever beam (DCB) and end notch flexure (ENF) specimens. The experimental data show that the cohesive parameters of Araldite 2015 have negative correlation to moisture content. Although Araldite AV138 parameters experience a decrease in mode I, in mode II, its cohesive parameter increases. First, it is found that the decrease in experimental failure load of mixed‐adhesive joints with regard to the dry condition is recorded as 32.6%, 54%, and 59.1% for E1, E2, and E3 conditions, respectively. Following this further, single lap joint (SLJ) that has non‐uniform moisture content distribution is modelled by engaging specific CZM parameters related to the specific moisture content. The results show a good agreement between experimental and numerical data.

Degradation prediction of mode I cohesive laws of hygrothermally aged CFRP adhesive joint using a direct method and accelerated aging

“…Similar trend of decrease in maximum traction with aging time for aluminum adhesive joint was observed in literature. [ 37 ]…”

“…A similar trend of decreasing fracture toughness and maximum traction values with aging is found in several studies. [ 2,17,37 ] Exposing adhesives to water might alter their properties and promote degradation, thereby degrading the joint strength. [ 7 ] Hence, the degradation is represented by the parameter, which is used to correlate the water diffusion data to the degraded TSL parameters.…”

On the static and fatigue life of nano‐reinforced Al‐GFRP bonded joints under different dispersion treatments

“…Adhesively bonded joints have major advantages over conventional joining techniques (bolting, riveting, and welding), namely, enabling a more uniform stress distribution over the bonded region, possibility to join dissimilar materials, eliminating stress concentration due to the holes in bolting, and no defects due to perforation in composite materials. Over recent years, these superior specifications led to widespread usage of bonded joints in various industries such as automotive, aerospace, marine, and wind turbine blade 1–7 . Therefore, it is needed to improve knowledge of adhesive joints mechanical behavior under special loading conditions by performing systematic researches.…”

Multi‐scale analyses on mechano‐electric degradation of film interconnects in flexible electronics

“…The CZM was originally introduced to investigate the fracture of brittle materials, and now, it is also widely used for ductile or composite materials. Zaeri and Googarchin 21 used bilinear CZM to analyze the behavior of single lap joints in moist conditions. Al‐Azzawi et al 22 developed a modified CZM with trapezoidal traction‐separation law to investigate the fatigue damage initiation and evolution of fiber‐metal laminates.…”