The National Academy of Engineering was founded in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. Army Tank-Automotive Research, Development, and Engineering Center (TARDEC), asked the National Research Council (NRC) to conduct a study under the auspices of the National Materials Advisory Board.
2 NEW MATERIALS AND PROCESSING OPPORTUNITIES 27
Strategy for Transforming the Army Truck Fleet, 16 Requirements for the Future Army Truck Fleet, 17 Role of New Materials in Meeting Future Needs, 23.
3 ENABLING NEW TECHNOLOGY INSERTION 55
APPENDIXES
ES-1 Overview of Opportunities for New Materials, Applications and Research, 4. a) Minimum Weight (Cost, Energy) Design: Stiffness and Strength, 34 (b) Minimum Weight (Cost, Energy) Design: Crack Length, 35.
INTRODUCTION
To address these goals, the committee was asked to perform the following tasks: investigate materials, processes, and structural concepts that would be candidates for advanced trucking. Army Tank-Automotive and Armaments Command (TACOM) to coordinate its advanced materials research efforts with industry and other federal agencies.
NEW MATERIALS AND PROCESSING OPPORTUNITIES
THE ARMY MUST FOLLOW THE USE OF LIGHTWEIGHT STRUCTURAL MATERIALS IN ITS TRUCK FLEET AS FOLLOWS:. The Army must clearly define the performance attributes that are important in its use of trucks.
COORDINATION OF RESEARCH
TO ACCOMMODATE THE TECHNOLOGICAL TRANSITION, THE ARMY SHOULD PARTICIPATE IN COOPERATIVE PROGRAMS WITH ADVANCED MATERIALS INDUSTRY CONSORTIA. Effective use can allow the military to assess the technical feasibility of new materials and technologies.
USE OF TRUCKS IN THE U.S. ARMY
S. Army Tank-automotive and Armaments Command
Army Tank-Automotive Command and was given control of almost all of the Army's tank-automotive systems. The age of the Army's existing fleet of trucks, known as the Legacy Force fleet, leads to problems in mobility for deployment, readiness and availability to support combat operations.
FUTURE ARMY TRUCKS
The state of the army between these two phases is called the Interim Force. The ability to transport army trucks using C-130 aircraft is a key performance characteristic of the Objective Force.
ROLE OF NEW MATERIALS IN MEETING FUTURE NEEDS
Lightweight materials can play a role in improved truck performance either by substituting stronger and/or lighter materials for traditional materials or by enabling new redesign concepts. Great efforts were required to certify new materials for use in combat vehicles because dynamic structural loads are largely unknown, many components are anisotropic, the combat environment is unique, and production must be tailored to vehicle requirements; and. Materials for automotive applications must be viewed as part of a system, in which appropriate compromises can be made.
Therefore, the report concluded, new benchmarks and strategies are needed to compare advanced material options and conventional materials for use in new generations of trucks.
ORGANIZATION OF THE REPORT
Secondary Structural Elements: The secondary structural elements are the parts of the truck that carry passengers and cargo, for example, the cab and cargo bed. It is of course essential that the truck's performance is not compromised by weight reduction. Improved joint designs also need to be developed to take full advantage of the benefits these materials can provide.
All common metal groups can be separated in an industrial process, and in fact a.
SHORT-TERM OPPORTUNITIES
In the commercial sector, the increased cost of an aluminum dump truck bed compared to a steel bed can often be justified due to the increased load capacity. Weight savings can be achieved by increasing the strength of the steel and reducing its mass. The challenge in using this technology is in justifying the price of the instruments for the relatively low production volumes of the military.
This technology can also work for military truck applications with the potential to eliminate 40 to 50 percent of spring weight.
MEDIUM-TERM OPPORTUNITIES
Selective use of advanced, commercially viable materials such as aluminium, magnesium, MMCs and polymer matrix composites (PMCs) can be beneficial in the medium term. Certain unresolved issues remain with the use of high strength steel alloys (i.e. TRIP, martensitic and dual phase), such as design optimization, material waste, tool investment and overall formability and springback (i.e. the tendency of a plate to relax when the forming loads are removed). The use of a single-sided, polyester molding tool at low pressure and a glass or carbon fiber preform in the VARTM process.
Several competitive, economically viable processing routes, such as lost foam casting, injection molding, semi-solid casting and rapid prototyping, have been demonstrated and implemented in the automotive industry.
LONG-TERM OPPORTUNITIES
When reinforced or blended with suitable particulate materials, such as SiC, titanium's strength and performance increase dramatically. Recent developments in processing technologies, such as cold hearth electron beam melting with a single melt and plasma arc melting, however, have significantly reduced the cost of titanium feedstock. Combining the use of single-melt Ti-6Al-4V with near-net shape processing and composition technologies such as casting, forging and powder metallurgy can further reduce fabrication costs.
Additive metalworking technologies such as laser-based mesh forming are being pioneered by companies such as Optomec, Laserfare and 52.
BARRIERS
The Army's goals for its truck fleet are to reduce logistics footprint, maintenance costs, and fuel load while maintaining other performance parameters. The military will need to reduce the use of heavy conventional materials such as mild steel and begin using lighter materials for primary and secondary truck structures. To reduce risk, the military should use the same practices used in commercial product development: computer simulation supported by prototype development and testing.
In addition, the Army should leverage appropriate technologies developed for commercial vehicles over multiple design cycles.
IMPROVED ARMY PROCUREMENT PROCESS
When personnel costs are included in operating costs, TACOM found that the total operating cost of the medium tactical truck was 66 percent of the total life-cycle cost.7 The operating cost of a recapitalized truck could be as high as 72.5 percent. The Army should develop a standard life cycle model that can be used in the acquisition process by both proposers and evaluators. An alternative type of procurement process could provide incentives to suppliers to produce products that maximize value to the Army.
The military could understand the utility function10 that governs truck use, and then compete its supply contracts in a way that rewards suppliers whose product maximizes the military's utility function.
IMPROVED MAINTENANCE SYSTEM
A utility function could provide the military with a single, quantitative equation that could be shared with suppliers and used to award procurement contracts. In addition, monitoring the condition of vehicles through inspection procedures can be used to plan preventive maintenance activities that will be maintained. Data on repairs and defective parts can be shared with manufacturers, enabling improvements to be made.
This combination could be achieved without increasing the total cost of ownership of the fleet for the next 20 years.
REDUCING THE COST OF NEW TECHNOLOGY
Despite these limitations, there are significant opportunities for the Army to use modularity in its truck designs. The Army has already used component standardization in some truck models - for example, using Steyr Symatec truck cabs from Austria. The Army would thus be able to take advantage of technological advances resulting from the many design cycles of.
In addition, unit procurement costs for the Army could be reduced by purchasing COTS products.
RADICAL REDESIGN ENABLED BY NEW TECHNOLOGIES
Previously, trucks were purchased directly from the commercial fleet and in some cases, such as that of the Commercial Utility Cargo Vehicle (CUCV), failed to meet military performance requirements. Using the hybrid electric powertrain reduces two major sources of inefficiency in engine-based transportation: the need to run an engine that is too large for the average application duty cycle, and the transient operation of the internal combustion engine caused by the drive wheel speed and required tractive effort. Finally, because the electric traction motor is designed to function as a generator during deceleration, some of the vehicle's kinetic energy is converted back into electrical energy.
Review of the research program of the partnership for a new generation of vehicles: seventh report.
LEVERAGING COMMERCIAL TECHNOLOGIES
The use of fuel cells as auxiliary power sources or, in the very long term, as primary energy sources would provide opportunities for new truck design and the deployment of radically new materials. The National Automotive Center is an existing Army program established in 1992 as part of the U.S.AAA that promotes collaborative research to accelerate the use of new aluminum technologies in automobiles and light trucks.
Review of the Partnership Research Program for a New Generation of Vehicles: Sixth Report.
OPPORTUNITIES FOR RESEARCH AND DEVELOPMENT
High-performance steels, magnesium alloys (transmission, gearbox housing and cover, engine block, suspension components), MMCs (drivetrain, brakes, wheels), PMCs (driveshafts, heavy-duty truck springs), high-performance castings, titanium springs, and more powerful tire cord. Short Term High Strength Steel, Stainless Steel, Galvanic Insulation, Corrosion Resistant Coatings and Design Stainless Steel (Truck Cabs), Aluminum Alloys (Truck Cabs, Cargo Boxes), Superplastic Molded Aluminum (Cab Structures), Magnesium Extrusions (Passenger Seat Frames), Sheet Molding Compound (Cab Components), Custom welded blanks (door panels) and corrosion design. Finally, military trucks for long-term applications can benefit from investments in titanium, smart materials and additive metal processes.
The Army should follow the guidelines in the "Summary of Opportunities for New Materials, Applications, and Research" table in this report.
FUTURE TACTICAL TRUCK STRATEGY
The Army should support the development of databases on the properties of these materials, as well as the development of models for processing lightweight materials and for predicting the performance of components manufactured using these materials. Unfortunately, the use of lightweight materials can increase the acquisition cost of a new truck, although the use of these materials can reduce life cycle costs through increased corrosion resistance as well as reduced energy consumption. THE ARMY SHOULD DEVELOP A LONG-RANGE FLEET-LEVEL PORTFOLIO STRATEGY THAT ESTABLISHES A SCHEDULE FOR ACQUISITION, REBUILDING, AND REPLACEMENT OF TRUCKS.
The program should establish concept development activities leading to the production of prototype demonstration vehicles.
BID SOLICITATION AND PROCUREMENT PROCESSES
LEVERAGING COMMERCIAL ADVANCES
SYSTEM FOR TRACKING VEHICLE AGE AND CONDITION
Currently, the age and condition of army trucks sent to such programs vary widely (Hathaway, 2001). A more standardized system for the replacement of damaged trucks would promote the introduction of new materials and technologies in the truck fleet.
TRACKING NEW MATERIALS FOR REPAIR AND DISPOSAL
He also served on numerous National Research Council committees and was a member of the National Materials Advisory Board. Automotive Research and a member of the National Research Council's Manufacturing and Engineering Design Committee. The hybrid electric powertrain offers solutions to two of the most significant sources of inefficiency in engine-based transportation.
By using a hybrid electric powertrain, the engine can be sized just right for the needs of average use.
