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For incorporating titanium components onto a vehicle in place of existing iron/steel components, there is a need for a methodical procedure to ensure successful and efficient integration. This involves a refinement over standard lightweight engineering procedures. In this paper, a suitable procedure is developed for replacing a structural component with titanium and the method realized. Design and manufacturing issues associated with integrating titanium are identified and addressed. The importance of justifying component replacement in terms of life-cycle costs rather than purely by the manufacturing cost alone is also emphasized.

Tires manufactured from polyurethane (PU) have been espoused recently for reduced hysteretic loss, but the material provides poor traction or poor wear resistance in the application, requiring inclusion of a traditional vulcanized rubber tread at the contact surface. The tread can be attached by adhesive methods after the PU body is cured, or the PU can be directly cured to reception sites on the rubber chain molecules unoccupied by crosslinked (vulcanizing) sulfur atoms. This paper provides a study of the two bonding options, both as-manufactured and after dynamic loading representative of tire performance in service. Models of each process are introduced, and an experimental comparison of the bonding strength between each method is made. Results are applied to tire fatigue simulation.

A state of the art proprietary method for aluminum-to-aluminum joining in the automotive industry is Resistance Spot Welding. However, with spot welding (1) structural performance of the joint may be degraded through heat-affected zones created by the high temperature thermal joining process, (2) achieving the double-sided access necessary for the spot welding electrodes may limit design flexibility, and (3) variability with welds leads to production inconsistencies. Self-piercing rivets have been used before; however they require different rivet/die combinations depending on the material being joined, which adds to process complexity. In recent years the introductions of screw products that combine the technologies of friction drilling and thread forming have entered the market. These types of screw products do not have these access limitations as through-part connections are formed by one-sided access using a thermo-mechanical flow screwdriving process with minimal heat.

The general manufacturing objective during the fabrication of automotive components, particularly through machining, can be stated as the striving to achieve predefined product quality characteristics within equipment, cost and time constraints. The current state of the economy and the consequent market pressure has forced vehicle manufacturers to simultaneously reduce operating expenses along with further improving product quality. This paper examines the achievability of surface roughness specifications within efforts to reduce automotive component manufacture cycle time, particularly by changing cutting feeds. First, the background and attractiveness of aluminum as a lightweight automotive material is discussed. Following this, the methodologies employed for the prediction of surface roughness in machining are presented. The factors affecting surface roughness as well as practical techniques for its improvement through optimizing machining parameters are discussed next.

Three-dimensional simulation has become an indispensable approach to develop improved understanding of ring rolling technology, with validity as the basic requirement of the ring rolling simulation. Cold ring rolling is simple conceptually, however complex to analyze as the metal forming process is subject to coupled effects with multiple influencing factors such as sizes of rolls and ring blank, form geometry, material, process parameters, and frictional effects. Investigating the coupled thermal and plastic deformation behavior (the plastic deformation state and its development) in the deformation zone during the process is significant for predicting metal flow in order to control the geometric and tensile residual stress quality of deformed rings, and to provide for cycle time optimization of the cold ring rolling process.

Due to titanium's excellent strength-to-weight ratio and high corrosion resistance, titanium and its alloys have great potential to reduce energy usage in vehicles through a reduction in vehicle mass. The mass of a road vehicle is directly related to its energy consumption through inertial requirements and tire rolling resistance losses. However, when considering the manufacture of titanium automotive components, the machinability is poor, thus increasing processing cost through a trade-off between extended cycle time (labor cost) or increased tool wear (tooling cost). This fact has classified titanium as a “difficult-to-machine” material and consequently, titanium has been traditionally used for application areas having a comparatively higher end product cost such as in aerospace applications, the automotive racing segment, etc., as opposed to the consumer automotive segment.

A new approach to lightweight engineering of vehicles focuses on identifying and eliminating Lazy Parts through the application of the Lazy Parts Indication Method (LPIM). In this context, Lazy Parts are defined as components that have the potential for mass reduction for a number of reasons discussed in previous literature. The focus of this research is to apply the LPIM to an automotive component, identify potential mass savings, and redesign the component to address the laziness and begin to validate the LPIM as well at the estimated mass savings. A generator mounting bracket for a vehicle is analyzed using the LPIM and redesigned. The application of the LPIM to the generator mounting bracket predicted an estimated mass savings of 10% (0.32kg), while the actual redesign of the bracket revealed a 12% (0.38kg) mass savings.

Current vehicle manufacturers must meet economic demands and design/manufacture more fuel efficient vehicles with increasingly better performance. As a result, they are turning to the use of more non-traditional lightweight materials in their products. One favorable material due to its excellent strength-to-weight ratio and high corrosion resistance is titanium. However, to warrant the replacement of traditional materials with titanium alloys there must be the benefit of reduced vehicle mass as well as performance enhancement gains from the substitution at a justifiable cost. In this work, an unsprung suspension component is selected and redesigned from the standpoint of (i) a direct material substitution and (ii) a material and requirements consideration based substitution. In addition, for the redesign of the component in titanium, the manufacturing procedure and process plan is integrated into the design phase for the component.

To warrant the substitution of traditionally used structural automotive materials with titanium alloys, the material substitutional and redesign advantages must be attainable at a justifiable cost. Typically, during material replacement with such ‘exotic’ aerospace alloys, the initial raw material cost is high; therefore, cost justification will need to be realized from a life-cycle cost standpoint. Part I of this paper highlighted the redesign, fabrication, and validation of an automotive component. Part II details the particulars of constructing the total life-cycle cost model for both prototypes (P1, P2). Considerations in the model include adaptation to a high volume production scenario, availability of near-net size plate/bar stock, etc. Further, response surfaces of fuel costs savings and consequent life-cycle costs (state-variables) are generated against life-cycle duration and unit fuel price (design-variables) to identify profitable operating conditions.