Parts Consolidation Research Articles

How It’s Made: A General Theory of the Labor Implications of Technological Change

This paper develops a general theory relating technology change and skill demand, capable of rationalizing the labor impacts of various technology changes since the 19thcentury. Performers (human or machine) face stochastic issues that must be solved in a given time to complete tasks. Firms choose how production tasks are divided into steps, the rate at which steps need to be completed, and the type of performer assigned to a step. Performers differ in the breadth of issues they can solve (generality) and in their tolerance for working at higher rates. Hu-man performers tend to be generalists with low rate-tolerance. Machine performers tend to be specialists less sensitive to rate. Central to the theory are the cost of fragmenting tasks into smaller steps, the cost of allocating performers to multiple steps, and the negative relationship between step complexity and the rate of completing that step. We derive the cost-minimizing division of tasks and level of automation of production and the demand for workers of different skills that those conditions create. Our theory predicts that the division of tasks under increased complexity is skill polarizing; automation is skill polarizing at lower production volumes and upskilling at higher volumes; and that parts consolidation increases the demand for mid-level skills. We find counterparts to the theory across a range of industrial contexts and time periods, including the Hand-Machine Labor Study covering mechanization and process improvement at the end of the 19thcentury, automotive body assembly, and emerging techno-logical changes in optoelectronic semiconductors used for communications.

Synergic Product and Process Design for Additive Fabrication of Lightweight Vehicles

<div class="section abstract"><div class="htmlview paragraph">Additive manufacturing is even more capturing the interest of vehicle manufactures. Its adoption enables design potentials such as parts customization, lightweighting or functional integration. Deep adoption of additive manufacturing and integration of topology optimization design techniques enable the calculation of light components, while additive manufacturing makes it feasible by adding subsequent layers of material. Design for additive manufacturing guidelines address these challenges by enabling the build of such complex shapes thanks to parts consolidation and features integration. Several prototypes of such lightweight design concerning chassis, body, and structures have been provided, but the lack of structured and objective approaches limits the application in normal production. This work integrates Key Performance Indexes (KPIs) into the Design for Additive Manufacturing (DfAM) approach for an effective adoption of selection of trade-off studies for the selection of best product variant and process setup. The trade-off involves KPIs related to structural product requirements and laser Powder Bed Fusion process cost estimation, to return functional components that address the best ratio between weight reduction and expected manufacturing cost. Proof of the method effectiveness and its application to lighten real components is demonstrated by applying the approach to reduce the weight of a steering support system for a Formula SAE race car. The objectivity of the trade-off promotes the extensive adoption to other vehicle components for substantial fuel efficiency improvement and emissions reduction perspectives.</div></div>

Parts Consolidation of Automotive Front Crossmember: From Two-Piece CFRP Design to One-Piece Design

<div class="section abstract"><div class="htmlview paragraph">As demand for fuel efficiency rises, an increasing number of automotive companies are replacing their existing metal designs with carbon-fiber-reinforced polymer (CFRP) redesigns. Due to the handling and manufacturing processes associated with CFRP materials, engineers have more design freedom to create complex, light-weight designs, which would be infeasible to manufacture using metal. Additionally, it is likely that by redesigning with CFRP, many steel assemblies can be consolidated to significantly fewer parts, simplifying or potentially eliminating the assembly process. When designing an automotive crossmember using CFRP materials, designers often aim for a two-piece design (top and bottom), while utilizing reinforcement material where needed. The joining of these two pieces is typically accomplished with many mechanical fasteners and adhesives, significantly increasing the part count and the manufacturing complexity. The objective of this research project is to redesign an existing steel front crossmember to a one-piece CFRP design, removing the need for most of the mechanical fasteners and adhesives. While a reduction in stiffness was observed in the final design, strength requirements were met, and the overall mass was reduced by over 25%. This work shows that a one-piece CFRP crossmember is possible and should be further explored in the automotive industry.</div></div>

Designing a Production-Ready Ultra-Lightweight Carbon Fiber Reinforced Thermoplastic Composites Door

<div class="section abstract"><div class="htmlview paragraph">Vehicle lightweighting has been a constant theme of research at numerous Original Equipment Manufacturers (OEM’s) as it provides one of the best opportunities for improving fuel efficiency. In this regard, the Department of Energy (DOE) Vehicle Technology Office set a challenge to lightweight a fully assembled driver’s side front door by at least 42.5% with the cost constraint of a maximum $5 increase for every pound saved. A baseline door of an OEM’s 2014 mid-size SUV was selected, and an integrated design, analysis, and optimization approach was implemented to meet this goal. The ultra-lightweight door design had to meet or exceed the fit & function and mechanical performance (static and dynamic) of the baseline door while being suitable for mass production. The design strategy involved parts consolidation, and multi-material distribution to enable mass reduction without compromising the fit and functional requirements. The primary structural component of this ultra-lightweight door design is a composite inner-frame made of a woven carbon/Nylon-6 composite material. While a finite element composite optimization technique was implemented to design the ultra-lightweight door that met the static and dynamic performance targets, it lacked manufacturing inputs. This study focuses on the feasibility of large-scale manufacturing of the composite inner-frame using thermoforming processes. One benefit of employing these processes is that the existing OEM stamping lines can be utilized with minor modifications with no additional capital cost for equipment. The scope of this paper is to identify the challenges in thermoforming of the thermoplastic door - including shear angle, tearing, and wrinkle formation - using draping simulation and share the solution in the form of countermeasures in the part design and tool concept to make the manufacturing of the final part feasible.</div></div>

Study on using generative and topology design for feature enrichment in Mars Rovers

Space travel has always been a crucial task. Exploration and experimenting on Planets in our solar system will help us understand the universe better and also, we could find the origin of life. Rovers play an important role in finding these answers. The problem we have at present is not only with technology to explore the universe but also the ability of our rockets to carry rovers to other rocks. Since a large amount of fuel is required for Space travel, we end with very little cargo that can be sent to explore. As additive manufacturing started to play a vital part in Mechanical Science, we are going to try to use that tool to build a Generative design that helps in parts consolidation, weight reduction, increase flexibility, design optimisation and cost consolidation. Since weight is an important aspect, we could reduce the present rover weight and add additional scientific tools to the rover to increase its scope of search and applications. This project focuses on features enrichment in Rovers by optimizing rover weight and design using Design for Additive Manufacturing concept.

Additive manufacturing of an automotive brake pedal by metal fused deposition modelling

This research is intended to study the possibility of implementing low-cost Additive Manufacturing (AM) technologies to produce metallic automotive brake pedal rapidly, covering the main aspects of design, material, and manufacturing. The main objective of this research is to explore new brake pedal design considering AM design freedom, parts consolidation with reduced mass, new AM material and application of metal-based AM fabrication technology. The most widely used AM technology, the Fused Deposition Modelling (FDM), has been used to produce metallic brake using the metal-polymer filaments followed by debinding and sintering processes. Finite Element Analysis (FEA) has been applied to analyze the feasibility of new brake pedal design for AM processing. The prototype of the FDM produced metal brake pedal has been physically tested to validate the FEA results and to evaluate the reliability of metal based FDM technology.

Investigating variations in the deep-sea sourcing strategies of car manufacturers: Two case studies of parts consolidation centers in Japan

This paper investigates how two Japanese car manufacturers organize their shipments of auto-parts from suppliers located in Japan to their overseas assembly plants. It reveals that, in addition to the well-known differences such as specific manufacturer-supplier relationships or production strategies, the organization of logistics itself constitutes a basis for persistent variations. Car manufacturers operating at a global scale are facing uncertainties in matching supply and demand, thus increasingly requiring flexibility. This flexibility is notably achieved through varying combinations of local and distant sourcing to respond to changes in market conditions, currency exchange rates, and so on. To limit the costs of distant sourcing, car manufacturers use parts consolidation centers, which are cross-docking facilities where parts are sorted and packed in sea containers depending on their final destination. Findings show that, beyond its generic purpose, the parts consolidation centers play different roles within the logistics organization of the two focal firms. In one case, they are highly integrated within the global production system; in the other, they are simply used as transfer points. These different models of utilization of parts consolidation centers imply significantly different relationships with parts’ suppliers, and point to wider differences in the overall logistics systems.

Not All Technological Change Is Equal: Disentangling Labor Demand Effects of Simultaneous Changes

We separate and directly measure the labor-demand effects of two simultaneous forms of technological change–automation and parts consolidation. We collect detailed shop-floor data from four semicon...

A Systems Approach in Developing an Ultralightweight Outside Mounted Rearview Mirror Using Discontinuous Fiber Reinforced Thermoplastics

<div class="section abstract"><div class="htmlview paragraph">Fuel efficiency improvement in automobiles has been a topic of great interest over the past few years, especially with the introduction of the new CAFE 2025 standards. Although there are multiple ways of improving the fuel efficiency of an automobile, lightweighting is one of the most common approaches taken by many automotive manufacturers. Lightweighting is even more significant in electric vehicles as it directly affects the range of the vehicle. Amidst this context of lightweighting, the use of composite materials as alternatives to metals has been proven in the past to help achieve substantial weight reduction. The focus of using composites for weight reduction has however been typically limited to major structural components, such as BiW and closures, due to high material costs. Secondary structural components which contribute approximately 30% of the vehicle weight are usually neglected by these weight reduction studies. This work is an attempt to prove that composites can also be used effectively in the weight reduction of secondary structural components, while meeting the desired standards on mechanical performance, cost, and scalability. Discontinuous fiber-reinforced injection-molded materials offer excellent mechanical properties and very high lightweighting potential. In this paper, a secondary structural component such as outside mounted rearview mirror assembly is used to study the effect of performance and cost while trying to achieve a mass reduction of at least 30%. An injection-molded long carbon fiber-reinforced nylon is used to replace the aluminum structure in the baseline mirror assembly. In addition to material replacement, 20%-parts consolidation was achieved due to the design freedom offered by these materials. A virtual plant layout was developed to determine the cost of series manufacturing. In conclusion, this paper provides a strong case for the use of these material systems to lightweight small and secondary structural components.</div></div>

Design Right Once for Additive Manufacturing

Additive Manufacturing (AM) has been widely considered a key factor for innovative design. However, the utilization of AM has not been as high as expected, although the technology offers key innovative design capabilities, weight reduction, parts count and assembly consolidation as well as material saving. This low utilization is attributed to the lack of AM understanding, mature CAE/CAM software tools addressing AM specific issues such as design support structure generation and removal, residual stresses, surface quality. In most cases, Design for AM (DfAM) is a crucial requisite for a “Design Right Once” approach. Such an approach is shown in the current study using three parts as example: an arthropod’s leg, a gearshift drum and an electric motor mounting frame. The implementation of geometrical conformal lattice structures and lattices with variable density are discussed. A structured design approach is presented and design dilemmas are solved in terms of a DfAM approach. Primary design optimizations are evaluated. Weight reduction is considered throughout the design and free form surfaces are being used. “Freedom to Design” principle is also portrayed and assembly parts consolidation occurs as a natural process of DfAM in comparison with previous design practices. It is concluded that, even from the primary design phase the design engineer can reveal his creativity because of the absence of constraints set by the traditional manufacturing technologies.

Collaboration delivers better results

As legislative requirements and customer expectations continue to rise, automotive manufacturers around the world are turning to proven suppliers to deliver new ideas as well as new materials. This collaboration can address complex issues such as lightweighting, parts consolidation, manufacturing efficiencies, comfort and safety. Download : Download high-res image (410KB) Download : Download full-size image

3D Deposition of Functional Materials for the Additive Manufacturing of Smart Devices

As is now widely recognized, Additive Manufacturing offers many potential advantages to both users and industry, with one of the principal benefits being in the extended levels of design freedom and complexity that can be incorporated into a component. For single material additive manufacturing – most notably the powder bed fusion techniques, which are of particular relevance and interest to industry today – we are beginning to see examples emerging that incorporate complex lattice structures or components that involve a degree of topology optimization or parts consolidation in their design. Though many of these emerging examples are impressive, by their single material nature, they also are limited to being used as “passive” components that require integration into a larger system in order to impart functionality beyond the mainly structural. However, taking the concept of design freedom beyond the geometrical domain to one where multiple materials are simultaneously deposited opens up the potential for the creation of functionalized, “active” devices “printed” in one build operation. However, though simple in concept, this discrete deposition of dissimilar materials throughout the volume of a part creates significant technical challenges, particularly in the deposition of useful materials.

Development of a design feature database to support design for additive manufacturing

PurposeThe purpose of this paper is to propose a method to aid design practitioners and students towards the design of additive manufactured products or parts produced using laser sintering (LS).Design/methodology/approachA design feature taxonomy was first developed as a guide for the development of a computer‐based design support tool. It comprised four taxons based on the reasons for utilising additive manufacturing (AM). These were user fit requirement, improved product functionality, parts consolidation and improvement of aesthetics or form. Each of the requirements was further expanded into 13 sub‐categories that contained examples of various design features that was then represented in the form of an MS Access database.FindingsResults from user trials of the database provide evidence to show the potential of the database, as it enables users to easily visualise and gather information about AM design features.Originality/valueThe paper describes a database, the aim of which is to serve as a collective source of information for design features produced by AM and as a method to aid the conceptual design process of AM parts or products.

Varying Lifecycle Lengths Within a Product Take-Back Portfolio

Product take-back and reuse is sometimes at odds with the rapidly evolving desires of some customers. For other customers, the environmental benefits of reuse more than compensate for minor drawbacks. “Selling a service” (rather than a product) through leasing enables the manufacturer to control the timing and quality of product take-back but current methods assume a fixed leasing period. What is needed is a method for fine tuning the time span of customers’ life cycles in order to provide each market segment the combination of features it most desires. This paper presents a new method for performing long range product planning so that the manufacturer can determine optimal take-back times, end-of-life design decisions, and number of lifecycles. The method first determines a Pareto optimal frontier over price, environmental impact and reliability using a genetic algorithm. Then, a multiattribute utility function is employed to maximize utility across different segments of the market and also across different lifecycles within each segment. Post-optimal studies help determine feasibility of component redesign in addition to parts consolidation. The proposed method is illustrated through an example involving personal computers.

Quantifying the effects of parts consolidation and development costs on material selection decisions: A process-based costing approach

Product designers must continually assess trade-offs among various performance attributes and cost. Materials choice can play an important role in that decision-making process. Materials affect many aspects of a product and firm—architecture, manufacture, and product performance. This paper examines the interrelationship of these early stage design choices through the application of process-based cost modeling. To capture the far-ranging effects of materials selection, models are presented which forecast the costs of development, manufacture, and assembly. A case study is detailed concerning two alternative material options for an automotive instrument panel beam: a conventional design (i.e., stamped steel) and a die-cast magnesium design which affords significant parts consolidation. Results indicate that parts consolidation led to both lower assembly and development costs. These cost reductions are shown to be a direct result of the consolidation of parts in the magnesium design.

Coupling of flow simulation and structural analysis for glass‐filled thermoplastics

AbstractIn the automotive industry, glass‐filled thermoplastics are used in air intake manifolds, radiator tanks, and many other parts. Plastic parts have many advantages over metal parts including mass, design flexibility and parts consolidation. However, widespread application of glass‐filled thermoplastic materials has been limited in many cases by the inability to accurately predict performance and durability. Fiber‐filled injection‐molded parts contain complex fiber orientation patterns. This fiber orientation state affects material properties including elastic modulus and strength and part properties including shrinkage and warpage. Tremendous amounts of time and money can be saved if one can predict the moldability and mechanical properties of a part at the design stage. In this work, we present a method where commercially available injection molding and structural analysis software may be coupled together with appropriate material property data to improve prediction of structural performance for parts molded from short glass fiber‐filled plastics. In addition, we compare the experimental and predicted performance based on simple equations and complex finite element calculations. Two major conclusions may be drawn from this work. In general, the assumption of geometric nonlinearity must be made. Also, an orthotropic material model is generally more robust and accurate than an isotropic analysis. Polym. Compos. 25:343–354, 2004. © 2004 Society of Plastics Engineers.

ISPAT INLAND DI-FORM 140T

Abstract Di-Form 140T is an ultrahigh-strength steel that offers a combination of high strength and high ductility, making it an excellent choice for parts consolidation programs. This datasheet provides information on composition, physical properties, and tensile properties. Filing Code: CS-137. Producer or source: Ispat Inland.

Stampable nylon sheets: Reinforcing with long glass fibers

Glass fiber reinforced thermoplastics have been utilized for many years in automotive and other high-performance applications. One of the newest processing methods for these materials is “stamping”, a process in which a reinforced thermoplastics sheet is heated and rapidly formed into a shaped object between matched metal dies. Advantages of products produced by this method include the following: parts consolidation, excellent strength, low cycle times even for very large objects, low finishing and tooling costs, and utilization of existing metal forming equipment. An extremely broad range of physical properties can be provided by tailoring both composition and construction of the composite sheets to the end-use requirements. The purpose of this paper is to discuss the material properties which can be achieved in stampable nylon-6 sheets as compared to corresponding injection molded compositions. The prime differences in composition between glass fiber reinforced stampable sheets and reinforced injection molded parts is the length and distribution of the glass fiber reinforcement utilized in each process. After injection molding, glass fibers are on the order of 0.015 to 0.030 in. in length, while after stamping the fibers may be of infinite length. This difference in length, in combination with the uniform fiber distribution obtained during stamping, leads to important improvements in heat and impact resistance and uniformity of properties.