Antanaitis D.B.,General Motors |
Riefe M.,General Motors |
Ciechoski C.,Durez Corporation |
Flaim T.,Complex Systems LLC |
Greening C.,Greening Associates Inc
SAE International Journal of Passenger Cars - Mechanical Systems | Year: 2013
The brake caliper piston plays a key role in caliper function, taking significant responsibility for qualities such as fluid consumption, insulation of the brake fluid from heat, seal rollback function, and brake torque variation sensitivity to disc thickness variation. It operates in a strenuous environment, being routinely subjected to high stresses and elevated temperatures. Given all of the demands on this safety-critical component (strength, stiffness, wear resistance, stable friction against rubber, thermal stability, machinability, manageable thermal conductivity, and more), there are actually relatively few engineering materials suitable for use as a caliper piston, and designs tend to be limited to steel, aluminum, and engineered plastics (phenolic composites). The lattermost - phenolic composites - has been of especial interest recently due to mass savings and possible reduction in brake corner judder sensitivity to disc thickness variation. This paper focuses on characterizing two important mechanical characteristics, stiffness and damping, of the most common piston materials, steel and phenolic. Data are shown first suggesting the effect of piston material on brake performance, and then stiffness and damping data from different methodologies are presented. From these data, a preferred methodology is recommended and results are reconciled with brake corner subsystem performance and modeling. Copyright © 2013 SAE International.
Nutt W.M.,Argonne National Laboratory |
Trail C.,Argonne National Laboratory |
Cotton T.,Complex Systems LLC |
Howard R.,Oak Ridge National Laboratory |
Van Den Akker B.,Oak Ridge National Laboratory
15th International High-Level Radioactive Waste Management Conference 2015, IHLRWM 2015 | Year: 2015
The evaluation of alternative UNF acceptance strategies resulted in several high level insights, identified additional analyses that should be performed, and identified necessary waste management system model enhancements. At a summary level, these are: Site-specific allocation/acceptance strategies could lead to significant benefits with respect to at-reactor management logistics and costs. Such strategies may allow for more efficient clearing of UNF from the reactor sites than would be attainable under an oldest-fuel-first allocation approach. Accelerating acceptance can also have benefits with respect to at-reactor management logistics and costs. Accelerating acceptance in combination with site-specific allocation/ acceptance could potentially be the most efficient approach for clearing UNF from the reactor sites. However, very aggressive allocation/acceptance strategies and rates would be challenging, if not impossible, to achieve considering the constraints associated with moving UNF at the reactor sites. Additional evaluation of UNF acceptance strategies is necessary to better understand their feasibility with respect to reactor site operations. Waste management system analysis tools need to be improved to better represent windows when UNF can be moved at the reactor sites. The strategy for accepting UNF from the reactor fleets will have an impact on the design, configuration, and operation of an ISF. The form of the UNF that would be accepted (canisters, bare fuel assemblies) and the rate the UNF is accepted will effect the number of canister/cask processing bays needed and the overall amount of UNF that would be stored at the ISF. The selection of an acceptance rate from the reactor fleet (i.e., 3,000 MTHM/yr) may influence the preferred strategy regarding the form of the UNF that would be accepted. From an overall system perspective, there may be advantages to accepting all UNF in dual-purpose canisters for acceptance rates on the order of 3,000 MTHM/yr. However, it may be beneficial to accept both bare fuel in re-useable transportation casks along with dual-purpose canisters if the acceptance rate is increased. Improved confidence in at-reactor UNF management costs along with better understanding of ISF design concepts would allow for better understanding of system impacts of different UNF allocation/acceptance strategies. The NFST is currently developing modular ISF design concepts for dry storage and the results from that effort can be implemented into future waste management system analyses. However, the development of ISF design concepts for bare fuel storage is not as mature. Constraints on UNF transportation casks/overpacks, such as thermal or radiation exposure limits, can have a significant impact on the ability to clear UNF from reactor sites for the different UNF allocation/acceptance strategies. These constraints are well understood for DPC systems. Designs designs certified by the U.S. NRC to meet the 10 CFR 71 requirements for re-useable transportation are limited and at present it was necessary to assume those constraints for large re-useable bare fuel casks transported via rail in the analyses completed to date. Bare fuel cask design concept development work underway should provide a better understanding of those constraints. The approach for loading DPCs in current system analysis modeling tools do not reflect how they are typically loaded or would be loaded at the reactor sites while taking thermal limits into account. The current waste management system analysis tools also do not estimate external radiation exposure on loaded transportation casks/overpacks for comparison with 10 CFR 71 limits. Efforts are being initiated to define these approaches and implement them into waste management system analysis tools.
Complex Systems Inc. | Date: 2012-11-15
Computer programs for use in banking and financial services for payments processing, namely, for ensuring secure messaging capability pertaining to financial transactions, and user manuals sold therewith.
Complex Systems Inc. | Date: 2001-08-24
Computer software for creating and transmitting to a bank funds transfer request forms which request the bank to act thereon.
Complex Systems Inc. | Date: 2002-07-02
Computer software for issuing and managing letters of credit and guarantee transactions online.