Showing 2 results for Keshavarzi
Hamidreza Ghasempoor, Ali Keshavarzi, Hamed Saeidi Googarchin,
Volume 13, Issue 4 (12-2023)
Abstract
The utilization of adhesively bonded square sections (ABSS) serves to enhance energy absorption and specific energy absorption (SEA) when subjected to oblique loading. Finite element models utilizing LS-DYNA were constructed in order to examine the deformation mode and load-displacement characteristics of ABSS and hybrid aluminum/carbon fiber reinforced polymer models. Subsequently, an evaluation was conducted on the general parameter pertaining to crashworthiness and the capacity for absorption of energy. The results reveal that an increase in the quantity of Carbon Fiber Reinforced Polymer (CFRP) layers within the stacking sequence of [0,90] affords enhanced potential for energy absorption. Conversely, the stacking sequence of [90] exhibits an incongruity with this trend, and achieves superior energy absorption capacity with a count of 4 CFRP layers rather than 8.
The present study indicates that carbon fiber reinforced polymer (CFRP) possessing a stacking sequence of [90] exhibits superior energy absorption capacity under both axial and oblique loading conditions at an inclination angle of 10 degrees. In contrast, the use of eight layers of CFRP with a stacking sequence of [0, 90] is found to yield better performance in achieving both axial and oblique loading up to 10 degrees.
Dr Ali Keshavarzi, Dr Hamed Saeidi Googarchin,
Volume 16, Issue 2 (6-2026)
Abstract
Adhesively bonded joints, particularly those featuring Carbon Fiber Reinforced Polymer (CFRP) adherends, have become indispensable in aerospace and automotive industries due to their superior strength-to-weight ratios. However, the long-term structural integrity of these joints is severely challenged by hygrothermal environments (the synergistic effect of moisture and temperature) which induces degradation in both the polymer matrix and the adhesive interface. This review provides a systematic discourse on the fundamental principles of composites, nanotechnology, and the mechanisms of environmental aging. It critically analyzes various joint configurations and failure modes, such as cohesive and adhesive failures, under adverse conditions. A significant portion of this study is dedicated to the efficacy of incorporating zero-, one-, and two-dimensional nanoparticles to enhance the environmental resilience of epoxy adhesives. Furthermore, this review evaluates the recent advancements in Cohesive Zone Modeling (CZM) for predicting the residual strength and fracture energy of aged joints through environment-dependent traction-separation laws. This work identifies critical gaps in accelerated aging methodologies and highlights the necessity for high-fidelity predictive models to ensure the safety of hybrid structures in high-stakes engineering applications.
