ScienceDirect Advanced molds and methods for the fundamental analysis of process induced interface bonding properties of hybrid, thermoplastic composites (original) (raw)
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The paper critically analyzed different interfacial enhancing methods used in thermoplastic composites. Although the absence of cross-linked polymer chains and chemical bonds on solidification enables the thermoplastics to be remelted, it creates weak interfacial adhesion between fibre reinforcements and the thermoplastic matrix. The weak fibre-matrix interface bonding reduces the efficiency with which the applied load can be transferred between these composite constituents, causing the composite to fail prematurely. Their need for high-temperature processing, poor compatibility with other polymer matrices, and relatively high viscosity render thermoplastics challenging when used to manufacture composite laminates. Therefore, various methods, including nanoparticles, changing the polarity of the fibre surface by plasma etching, chemical treatment with ozone, or an oxidative attack at the fibre surface, have been applied to improve the fibre/matrix bonding in thermoplastic composites...
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Joining is a key enabler for a successful application of thermoplastic composites (TPC) in future multi-material systems. To use joining technologies, such as resistance welding for composite-metal joints, auxiliary joining elements (weld inserts) can be integrated into the composite and used as an interface. The authors pursue the approach of embedding metal weld inserts in TPC during compression moulding without fibre damage. The technology is based on the concept of moulding holes by a pin and simultaneously placing the weld insert in the moulded hole. Subsequently, the composite component can be joined with metal structures using conventional spot welding guns. For this purpose, two different types of weld inserts were embedded in glass fibre reinforced polypropylene sheets and then welded to steel sheets. A simulation of the welding process determined suitable welding parameters. The quality of the joints was analysed by microsections before and after the welding process. In ad...
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Ultrasonic welding is a promising assembly technique for thermoplastic composites and it is wellsuited for spot welding. In this paper, the in-plane and out-of-plane mechanical behaviour of ultrasonically spot-welded and mechanically fastened joints are investigated by double-lap shear and pull-through tests, respectively. Special attention was paid to the comparison of onset failure load and joint stiffness of both types of joints in either type of test. Fractography was utilized to analyse the teste specimens. Failure of welded specimens was found limited in the joints but catastrophic damage was introduced into composite substrates of mechanically fastened specimens. The possibility of the substitution for mechanically fastened joints by spot-welded joints is discussed.