The joining techniques for thermoplastics materials in automotive industries: A comprehensive literature review

Bu çalışma,11-17 Kasım 2016 tarihlerinde Arizona[Amerika Birleşik Devletleri]’da düzenlenen ASME International Mechanical Engineering Congress and Exposition (IMECE2016) Kongresi‘nde bildiri olarak sunulmuştur.Nowadays the use of thermoplastic materials has been increasing steadily, especially in automotive industries because of its positive effects on vehicle weight which is directly related to fuel consumption. These materials also provide a cost reduction for companies comparing with the steel or other similar materials. The other benefits of the thermoplastic materials are their high stiffness, excellent crashworthiness due to their energy-absorption characteristics, strength-to-weight ratios, fatigue and optimum design. Through their structure occurred by the polymer resins, thermoplastic materials can physically become a homogenized liquid when heated and hard when cooled. The thermoplastic materials are able to reheat, remolded and have good thermal and chemical stability. Also, these materials can be easily recycled which provides a lower environmental impact on the automotive industry. Due to the advantages of the thermoplastic materials, automotive industries have been using these technology in vehicle parts such as door panels, seat backs, load floor, engine cover, front end module, airbag housing, crash boxes, bumpers, instrument panel, air intake manifold, air duck, cross car beam, pedal brackets, gas tank carrier, etc. In order to produce the thermoplastic materials, a number of different methods (i.e. mechanical fastenings, ultrasonic assembly, metal inserts, snap fits, electromagnetic and heat welding, solvent/adhesive bonding) are proposed in the literature and most of them are successfully carried out in industrial applications. However, the identifying the joining technique according to the application area is an important issue to obtain appropriate material. Therefore, this paper presents a literature review of joining methods for thermoplastic materials and classifies the methods according to the structure of the joining technique. Within this context, more than 50 studies about joining techniques for thermoplastic materials are considered the methods are grouped into three main categories: chemical joining techniques, mechanical joining techniques, and thermal joining techniques. Chemical joining methods melt the surfaces of the materials by using a chemical solvent. By using the solvent, one plastic material is joined to itself or the material is joined to another type plastic that dissolves in the same solvent. In mechanical joining techniques, the materials are "bonded by using some physical methods such as clipping, clamping, screwing, riveting, etc. Similarly, in thermal joining techniques the surface of the materials to be joined are heated and a pressure is applied until the thermoplastic material is formed. As a result of the review, the differences and efficiency of the joining methods are pointed out in the study with paired comparisons. Moreover, the real life applications of joining methods for thermoplastic materials in the automotive industry are presented. In this paper, effects of the joining techniques on pedestrian and occupant safety are also reviewed by taking into account the high-stress concentration factor, the inconvenient manufacturing process and, the reaction force peaks. Finally, the future challenges of the three categorized are summarized.Amer Soc Mech EngineersFİAT-TOFAŞ otomotiv şirket

Hafif ticari bir araç için ön burun taşıyıcı modül geliştirme

CO2 emission targets became a crucial obstacle for vehicle producers. In order to overcome this problem, weight reduction potentials are getting more and more critical. In this study, for a light commercial vehicle, a glass fiber reinforced thermoplastic front-end structure has been analyzed. At first, a fully plastic draft design is analyzed and compared with the current metal structure. After that, a topology volume is extracted from the existing vehicle structure, and topology optimizations have been carried out according to the modal and static loading performance targets. Different optimization parameters have been investigated to decide the best solution in terms of performance and weight. Load paths and optimum design are calculated by topology results. Due to the packaging problems with the radiator and headlamp, optimization volume is modified, and the new topology volume and optimizations are completed. Based on the topology results, a feasible design is prepared, and detailed non-linear analyses are started. After the non-linear analyses, free size optimization is applied to the ribs of the part. In this study, a feasible preliminary design at the same performance with less weight respect to the current metal version is completed.CO2 emisyon hedefleri araç üreticileri için aşılması gereken en önemli engellerin başında gelmektedir. Hedefe ulaşmak için gerekli potansiyeller biri olan araç hafifletmenin önemi gün geçtikçe artmaktadır. Bu çalışmada, hafif ticari bir araç için cam elyaf takviyeli termoplastik ön burun taşıyıcı modülü sonlu elemanlar analizleri kullanılarak geliştirilmiştir. İlk aşamada, geliştirilen termoplastik tasarımın analizleri gerçekleştirilmiş ve mevcut durumda kullanılan metal yapı ile karşılaştırılmıştır. Daha sonra, mevcut yapıdan paketleme ile montaj kısıtları dikkate alınarak bir topoloji dizayn hacmi çıkarılmıştır. İlgili hacim kullanılarak doğal frekans hedefleri ile yapısal performans kriterleri dahilinde topoloji optimizasyonları gerçekleştirilmiştir. Optimizasyonlar sırasında performans ve ağırlık açısından optimum çözüme ulaşabilmek için farklı parametrelerin etkisi araştırılmıştır. Topoloji optimizasyon sonuçları kullanılarak optimum tasarım ve yük yolları belirlenmiştir. Radyatör ile far arasında değişen paketleme kısıtları nedeniyle optimizasyon hacmi değiştirilerek yeni bir topoloji dizayn hacmi oluşturulmuş ve topoloji optimizasyonları tekrarlanmıştır. Optimizasyon sonuçlarına göre yeni bir tasarım oluşturulmuştur. Bu tasarım kullanılarak doğrusal olmayan yapısal analizler gerçekleştirilmiştir. Analizlerin ardından yeni tasarımdaki federlerde kalınlık optimizasyonu yapılmıştır. Bu çalışmada, mevcut metal versiyonuna göre daha hafif olan ve aynı performansta sahip termoplastik bir ön burun taşıyıcı modülü geliştirilmiştir