Manufacturing Car Body - Term Paper Example

CAR BODY PROCESSING Table of Contents Introduction 3 Design 3 Requirements of material used in automotive 5 Lightweight 6 Cost 6 Safety and crash worthiness 7 Recycling and life cycle considerations 7 Materials used in car body 7 Body component processing 11 Tempering 11 Press Processing 11 Weld processing and assembly 11 Precision press processing 11 Non-contact Three-dimensional Measuring 12 Tailored Blank Welding 12 YAG Laser Welding 12 Hot stamping 12 Conclusion 12 List of references 13 Introduction The manufacture of cars is a technology that requires shear expertise throughout the design, material selection, and material processing, and assembling of parts. Car body manufacturing and assembling require specific properties and characteristics. Moreover, there are specific materials that can be used in car bodies. The material selection has evolved in the automotive industry right from the primitive materials and processes to modern innovation materials and sophisticated processing technologies. Materials used to make car bodies can be steel, aluminium, and magnesium including their alloys obtained through further processes and a mix of materials. Different materials undergo different manufacture processes. Tempering process is used for iron-alloy by heat treatment. Other processes are welding, pressing, and machining. Car body manufacture follows simple requirement of cost efficiency and objective achievement. The tradeoff here will always ensure that the car produced is stable, cheap, consumes less fuel. Design Designing a car involves looking and examining that the car design observes various impending issues like aerodynamic efficiency, overall weight, and balance, engine power, materials to be used in the production of certain parts. Using the basic principles of aerodynamic, car body shape should be an airfoil to be able to cut through air (Omar 2010). Figure 1 aerodynamic property of body shapes Figure 2 Recommended car body design mindful of aerodynamic properties To achieve car balance is largely influenced by the chassis material and shape used, wheel orientation, and engine setup. All this factors add up to the full package and must be critically analyzed to ensure car produced meets standards, is safe, and cheaper to construct, purchase, and operate. Geometrical shape of the vehicle affects locomotion. When a vehicle of block body is constructed tradeoff of high engine power comes into play. In the design of fast moving cars airfoil, shaped object is of priority. Figure 3 chart representation of traction, acceleration, resistance, and maximum engine power Carefully studying the properties above goes along way into developing a model car that meets standards. From the chart, it can be deduced that cars at very high speeds have very low force of acceleration and reducing maximum power of the engine. Of relevance to body, design is air resistance, which increases as velocity increases (Jiangqi Zhou 2008). Requirements of material used in automotive Materials put to use in the manufacture of cars must fulfill certain conditions. Constraining factors are the requirements dictated by car requirements for movement. Others influencing factors are regulation and legislations for environment conservation and safety concerns. Some of the most basic requirements are that the car body should be of lightweight, cheaper, safe during crash situations, and materials should be recyclable. Lightweight To reduce carbon emission and the green house effect, cars need to reduce fuel consumption greatly and as such should have lightweights. The limiting factor in use of strong lightweight materials is the cost associated with such materials. Research shows that for every 10% weight reduced fuel consumption reduces by 7%. By deduction here, every kilogram of weight reduced means carbon emission is reduced by 20 kilograms. To achieve lightweight the use of aluminium sheets for car bodies goes an extra mile from the other materials hence the most effective. However, this material means trading off rigidity for lightweight (Ashby 2010). Another material is the use of steel pressings, which are strong and stiff. Cost This factor is consumer driven. Cost in the automotive industry is a combination of three individual costs. These are the actual raw material cost, the cost of manufacturing, and the design and test of product costs. In the industry, the cost of aluminium and magnesium alloys is extremely high in comparison to steel and cast iron. To attain market competitiveness, costs must be at a minimum level. Cast irons and steel are very costly compared to cast aluminium and magnesium components. This is because they have reduced manufacturing time, better Machinability, have the ability to be thinner, and allow more variable wall dimensions. The material can achieve closer dimensional tolerances, less number of assemblies, easily produced to shape hence reducing on body finishing costs, and the fact that melting processes is less costly (Omar 2010). Since cost is deemed higher, the choice of light metals has to be ascertained on improving functionality. Safety and crash worthiness This is the ability of a car body to absorb and swallow impact energy to safeguard the passenger. The safety standards considered here are crashworthiness and resistance to penetration. Crashworthiness is designed to allow the body to provide gradual decay of load weight during the absorption process. Currently, car passengers should not attain 20gs at speeds of up to 15.5m/s under impact with an immovable object. Deformation is as a result of material used but under this case the mechanism and sequence the damage occurs mostly incline towards the geometry of the body, lamina setup, trigger, and crush speeds. Design can be geared towards achieving higher absorption capacities. Material properties like stiffness, yield, strain hardening, and elongation are key properties to keep in mind. Geometries of the front side members like closed-hat, double-U, and octagonal columns should be made of conventional steel, high-strength steel and light alloys joined with different methods (S. C. Bruckmeier 2012). Recycling and life cycle considerations With increased awareness of the environment, material recycling sets into the picture during manufacture. Key issues towards recycling include protection of resources, reducing emission of carbon dioxide. Use of hazardous material is prohibited in some countries and morally should not be used. Innovation has led to development of new manufacture processes for materials to minimize their effects on the environment. Some materials react in the environment resulting in rust and other harmful emissions. Materials used in car body In building of vehicle bodies, metals are mostly used. However, technology has slowly resulted into the use of plastics and other composite materials. Lightweight steel are used together with iron through technologies. Iron and steel make up the critical elements of body structure for the many produced vehicles owing to their low material cost with a wider experience and familiarity with the industry. Properties of materials are categorized as either under tension or compression. Among the most fundamental properties are yield and tensile strength, fracture, anisotropy and Young’s modulus. Metals for body application are made into sheet shapes because their strength is then improved. Depending on the loading conditions, material and shape properties are combined in order to achieve resistance to loads applied. In axial tensile the part shape is not of concern as contrasted with the cross-sectional zone. The quality of a part that ought to be under pivotal stacking is identified with the mechanical properties of the material. In torsion and bending, both material and shape are imperative parameters for the effectiveness of the part to convey the connected burden. For bowing, the flexible plastic move is a blending of shape and material properties. The quality of a pillar under curving is identified with the materials yield anxiety and Youngs modulus. There are an expansive reach of chances for utilizing aluminum in car powertrain, undercarriage, and body structures. The utilization of aluminum offers respectable potential to diminish the weight of a vehicles body. Aluminum compounds picked for outer surface boards must have the capacity of age solidifying to give suitable quality to imprint safety throughout the broiler paint preparing. The consumption safety of present day, magnesium compounds is superior to that of traditional aluminum. In addition, without porosity, the die-cast Am501 Am60 can accomplish 20% prolongation, or in excess of three times that of Al A380, prompting higher sway quality; yet magnesium segments have numerous mechanical/physical property detriments that require uniqueness in design. Despite the fact that its malleable yield quality is about the same, magnesium has more extreme rigidity, fatigue strength, and creep quality contrasted with Aluminum. The modulus and hardness of magnesium composites is easier than aluminum and the warm extension coefficient is more amazing (Ashby 2010). Table 1 Alternative materials and potential weight saving versus cost (source: Corus Automotive Eng., 2010) Figure 4 Comparison of specific stiffness and strength of Mg, Al, and Fe (Source: Kulekci, 2008) Table 2 Specific Strength of stainless Steel, 6061 Aluminium, and High Strength Steel (Source: Cunant, 2000) Body component processing Tempering Is a procedure of treatment using heat, which is utilized to build the toughness of iron-based alloys. Treating is normally performed after hardening, to lessen a percentage of the excess hardness, and is carried out by warming the metal to some temperature beneath the basic temperature for a certain time, then permitted to cool in still air. The definite temperature decides the measure of hardness removed, and relies on both the particular structure of the compound and on the required properties for the finished product (Barry manufacturing process). Press Processing Made use of here are press machines and coil press lines in development of materials. In addition, the assembling of press dies, which are fundamental parts, attains high productivity and high quality of creation in stamped items. Weld processing and assembly Different parts made in the press procedure are amassed into casing segments of the auto and items around the cabin. Different parts are joined together through the process of welding. Precision press processing In the case of heavy metal use, there is need to perform finer pressing procedures to ensure that the finished product is unique and of high quality. This can be realized by making full use of available forging presses and sometimes servo transfer processing. Automated solid design configuration of press dies, the heart of superb assembling of auto body press parts production, is performed utilizing mechanized die design program created in-house. Non-contact Three-dimensional Measuring This is a toll used to perform a complete body checks for accuracy. It is used for examining complex curved surfaces, shipping inspection, using three-dimensional instruments for measurement. Tailored Blank Welding This is a procedure for fusing together thick steel plates in sections that require higher strength and of thin walls. This is done before pressing to create rigid and metal of lightweight. YAG Laser Welding It is utilized within precision handling utilizing very small spot and stable density laser shafts. It is astoundingly appropriate for difficult processing work, welding of hard and brittle materials, and transforming new materials. YAG laser welding generates small twisting, because of high temperature, making it additionally ideal for micro-manufacture (Barry manufacturing process). Hot stamping Hot stamping is the procedure of solidifying materials by press forming a steel plate warmed to a high temperature and cooling it rapidly in a mold to make products of high quality. To produce a lightweight and exceedingly unbending body, hot stamping is a significant strategy together with the usage of super high-pressure materials (Barry manufacturing process). Previously, hot stamping used to be a high-taken a toll method acknowledged unacceptable for large-scale manufacture because of its low preparing rate and the trouble in welding the solidified item. Conclusion The opposition in the business of materials for auto provisions is significant. This is because of the size and quality of the business sector. In the later years, the ecological concern has opened the need for lighter vehicle for easier fuel utilization and likewise for the need of reusing. These late weights have opened the entryway for acquaintance of new materials with the auto market. The universal materials, for example, steel makers are making a decent attempt to keep their business sector by further advancements and changes in steel. This is through alloying and their procedures with a specific end goal to offer lighter material and structure choice. Anyhow, in the meantime the more up to date materials, for example, elective metals and composites are at the heart of the examination and improvement for opening the likelihood of the lighter and even better disposed future vehicles. Aluminium offers the best properties for lighter bodies. Steel sheets offer the best properties for cheap car bodies. List of references ASHBY, Michael F. (2010). Materials Selection in Mechanical Design. vol.1. 4 ed., New York, Butterworth-Heinemann. Butterworth-Heinemann, 1856176630. BARRY, Keith (manufacturing process). Car body design. [online]. Last accessed 9 April 2014 at: http://www.carbodydesign.com/publications/manufacturing-processes/ JIANGQI ZHOU (2008). Application of Axiomatic Design Method to Manufacturing Issues Solving Process for Auto-body. vol.3. 2 ed., London, Springer London. Springer books, 2. OMAR, Mohammed A. (2010). Automotive Body Processing. vol.2. 3 ed., Kenturcky, John Wiley & sons Inc. John wiley, 3. S. C. BRUCKMEIER (2012). Car Body Design with Polyurethane Composites Produced by an Innovative Pultrusion Process. vol.2. 1 ed., Chicago, Springer Berlin Heidelberg. Springer Berlin Heidelberg, 3. Read More