SEARCH RESULT

Carbon fibre reinforced composites (CFRP) generate increasing interest automobile industry, especially for electrical and hybrid vehicles in recent years due to their high specific stiffness and specific strength to weight ratios, high fatigue properties and design optimisation in different directions as dictated of the structural component. Carbon fibre reinforced composites are generally 30% lighter than aluminium and 50% lighter than steel [1]. Fabrication of car components with composite materials, however, needs specially designed joints in assemblies of structural components. In this respect, joints have crucial importance because they act as a transfer member where high stress concentrations and potential failures can occur during fatigue life of joined structures [2]. The design of joints strongly depends on geometrical parameters, joint materials and their properties (stiffness, strength) and properties of fasteners (rivets, bolts, pins) and adhesive materials (epoxy). Lap joints were commonly characterised by different design factors in laminar composites. However, the limited numbers of study are available with these design parameters in tubular composites. Previous studies calculated theoretical analysis of tubular lab joints in tension load and investigated the effect of adhesive layer thickness in terms of shear and normal stresses. They showed the infinite number of shear and normal stresses in overlapping ends. However, most of the study was limited to isotropic material properties in FEM and analytical results [3, 4]. Jena and Pradhan were also applied FEM model adhesively connected joints on composite tubes in terms of thickness, overlap length and adhesive end fillets. They showed that optimum overlap length of 20-25 mm. The stress concentration values in CFRP composites were found less than isotropic material when an overlap length is more than to be of 20 mm. The optimum adhesive thickness also found to be 0,25 mm. The triangle and elliptical shape of end fillets of adhesive enhanced the joint strength [5].

International Symposium on Light Alloys and Composite Materials
UHAKS

Mustafa ASLAN

Wood plastic composites as an alternative to traditional wood and wood based composites can be used outdoor applications with higher physical and biological properties such as durability and higher resistant to fungi, biocides. The use of recycled chemically treated raw materials can also help to increase these properties for harsh environmental conditions. WPCs are fiber-reinforced composites produced by mixing wood components and polymers. In a WPC, a polymer forms a continuous matrix that surrounds the reinforcing wood components. The low price and high stiffness of wood make it an attractive reinforcement for the commodity plastics [1]. The way of processing of WPCs is similar to the plastic, there are several appropriate manufacturing technologies available for WPCs. In spite of the fact that, the majority of WPC products are extruded, injection and compression molding are other major technologies used in WPC production [2].

International Symposium on Light Alloys and Composite Materials
UHAKS

Muhammed Dalu Ertuğul Altuntaş Mustafa ASLAN Ali Temiz

Additive manufacturing (AM) technology can be performed quickly without the expense of labor and mold. The design of the core materials have been playing a significant role on the production of sandwich composites besides as core material, the use of an auxetic pattern instead of honeycomb pattern can increase the compression strength of the sandwich composite materials. Therefore in this study, the effect of different geometry investigated on compression strength of Acrylonitrile butadiene styrene (ABS). The design of Re-entrant, Star and Missing rib patterns have been used as the auxetic patterns for the design of the core materials by FDM (fused deposition melting) type of 3D printer. The different geometry effects on the compression strength of the auxetic core material were evaluated with different cell lengths and wall thicknesses. After the manufacturing of solid core materials in the 3D printer, these materials have been subjected to edgewise compression tests. The obtained the results have been discussed presenting different values of the compression strength due to the effect different geometry and thicknesses. While the best compression properties were achieved with the ABS auxetic core material with the wall thickness of 1 mm and cell length 6 mm. Moreover, the best edgewise compression performance was achieved re-entrant pattern in the auxetic core structures and circle pattern in the cellular core structures.

International Congress on 3D Printing (Additive Manufacturing) Technologies and Digital Industry
3D-PTC2019

Mustafa ASLAN Kutay CAVA Ümit ALVER Hasan Gedikli