Automotive Science and Engineering

---

Automotive design engineers face the challenging problem of developing products in highly competitive markets. In this regard, using conceptual models in the first step of automotive development seems so necessary. In this paper, to make a body in white conceptual model, an engineering approach is developed for the replacement of beam-like structures, joints, and panels in a vehicle model. The proposed replacement methodology is based on the reduced beam, joint, and panel modeling approach, which involves a geometric analysis of beam member cross-sections and a static analysis of joints. In order to validate the proposed approach, an industrial case-study is presented. Two static load cases are defined to compare the original and the concept model by evaluating the stiffness of the full vehicle under torsion and bending in accordance with the standards used by automotive original equipment manufacturer (OEM) companies. The results show high accuracy of the concept models in comparison with the original model in bending and torsional stiffness prediction.

---

Connecting point of the longitudinal veins and cross-veins in wing is called Joint.  In some insect wing joints, there is a type of rubber-like protein called Resilin. Due to the low Young's modulus of this protein, its presence in the wing can help to change the shape of the wing during flight. Today, using composite structures in flying vehicles in order to achieve the desired shape of wing is considered. The purpose of this study is the multi-objective optimization of artificial wing by arranging Resilin joints in the artificial wing of Micro air vehicles (MAVs). The amount of torsion and bending of the flapping robot wings is considered as the objective function to improve the flight performance of robots. Two types of artificial wings have been investigated, and considering pareto points, the optimal arrangement of Resilin joints has been achieved.  The result of this study shows that in both wings, with the presence of Resilin in the joints, the amount of torsion has increased to 38.65 degrees.
 

---

The aim of the study was to examine the deformation modes and also degradation of an adhesively bonded rectangular cross section beam used in the automotive body structure. The study included: (1) performing new experimental investigations on the three-point bend behavior of a rectangular cross section beam made by adhesive bonding method. (2) developing a finite element (FE) model to predict the mechanical load displacement behavior and also the degradation modes (i.e. delamination between the adhesive layer and beam wall). The agreement between experimental and FE results demonstrates that the investigated structural element's numerical model was created utilizing accurate assumptions. Finally, the effects of beam wall thickness and overlap length have been investigated in a parametric study using the validated FE model. It was shown that increasing the beam wall thickness resulted in delamination between the adhesive layer and beam wall.

---

This paper presents an experimental study on the effect of adhesive thickness on the maximum load of adhesive joints under static and impact loading, using the double cantilever beam (DCB) test method. The DCB specimens were prepared with varying adhesive thicknesses and subjected to impact loading using a drop weight impact tester. The maximum load was recorded for each specimen. The results indicated that the maximum load of the adhesive joints increases with increasing adhesive thickness up to 5 mm, beyond which the maximum load decreases with further increase in adhesive thickness. Moreover, the failure mode of the adhesive joint was found to be strongly dependent on the adhesive thickness, with thicker adhesive layers exhibiting an adhesive failure mode but in thinner thicknesses, the adhesive mode is cohesive. These findings provide important insights into the design and optimization of adhesive joints for applications that are subject to impact loading.