| 1. |
- Kokkolaras, Michael, et al.
(författare)
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Design Under Uncertainty and Assessment of Performance Reliability of a Dual-Use Medium Truck with Hydraulic-Hybrid Powertrain and Fuel Cell Auxiliary Power Unit
- 2005
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Ingår i: 2005 SAE world congress. - Warrendale, Pa : Society of Automotive Engineers, Incorporated.
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Konferensbidrag (refereegranskat)abstract
- Medium trucks constitute a large market segment of the commercial transportation sector, and are also used widely for military tactical operations. Recent technological advances in hybrid powertrains and fuel cell auxiliary power units have enabled design alternatives that can improve fuel economy and reduce emissions dramatically. However, deterministic design optimization of these configurations may yield designs that are optimal with respect to performance but raise concerns regarding the reliability of achieving that performance over lifetime. In this article we identify and quantify uncertainties due to modeling approximations or incomplete information. We then model their propagation using Monte Carlo simulation and perform sensitivity analysis to isolate statistically significant uncertainties. Finally, we formulate and solve a series of reliability-based optimization problems and quantify tradeoffs between optimality and reliability. The most relevant design parameters of the diesel engine, fuel cell, driveline and vehicle are considered. The results demonstrate the necessity for addressing uncertainty to make valid assessments and design decisions
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| 2. |
- Michelena, Nestor, et al.
(författare)
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Design of an Advanced Heavy Tactical Trucks : A Target Cascading Case Study
- 2001
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Ingår i: International Truck and Bus Meeting and Exhibition. - Warrendale, Pa : Society of Automotive Engineers, Incorporated.
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Konferensbidrag (refereegranskat)abstract
- The target cascading methodology is applied to the conceptual design of an advanced heavy tactical truck. Two levels are defined: an integrated truck model is represented at the top (vehicle ) level and four independent suspension arms are represented at the lower (system ) level. Necessary analysis models are developed, and design problems are formulated and solved iteratively at both levels. Hence, vehicle design variables and system specifications are determined in a consistent manner. Two different target sets and two different propulsion systems are considered. Trade-offs between conflicting targets are identified. It is demonstrated that target cascading can be useful in avoiding costly design iterations late in the product development process.
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