排序方式: 共有223条查询结果,搜索用时 15 毫秒
221.
Reliability-based topology optimization based on bidirectional evolutionary structural optimization using multi-objective sensitivity numbers 总被引:1,自引:0,他引:1
K. -H. Cho J. -Y. Park S. -P. Ryu J. -Y. Park S. -Y. Han 《International Journal of Automotive Technology》2011,12(6):849-856
Reliability-based topology optimization (RBTO) is used to obtain an optimal topology satisfying given constraints, as well
as to consider uncertainties in design variables. In this study, RBTO was applied to obtain an optimal topology for the inner
reinforcement of a vehicle’s hood based on bidirectional evolutionary structural optimization (BESO). A multi-objective topology
optimization technique was implemented to obtain the optimal topology for two models with different curvatures while simultaneously
considering the static stiffness of bending, torsion, and natural frequency. A performance measure approach (PMA) with probabilistic
constraints formulated in terms of the reliability index was employed to evaluate the probabilistic constraints. The optimal
topology obtained by RBTO was evaluated and compared to that obtained by deterministic topology optimization (DTO). A more
suitable topology was obtained through RBTO than DTO even though the final volume obtained by RBTO was generally slightly
greater than that obtained by DTO. The multiobjective optimization technique based on BESO can be applied very effectively
with topology optimization for a vehicle’s hood reinforcement. 相似文献
222.
C. L. Myung J. Kim S. Kwon K. Choi A. Ko S. Park 《International Journal of Automotive Technology》2011,12(3):331-337
This study was conducted for the experimental comparison of particulate emission characteristics between the European and
World-Harmonized test cycles for a heavy-duty diesel engine as part of the UN/ECE PMP ILCE of the Korea Particulate Measurement
Program. To verify the particulate mass and particle number concentrations from various operating modes, ETC/ESC and WHTC/WHSC,
were evaluated. Both will be enacted in Euro VI emission legislation. The real-time particle emissions from a Mercedes OM501
heavy-duty golden engine with a catalyst based uncoated golden DPF were measured with CPC and DMS during daily test protocol.
Real-time particle formation of the transient cycles ETC and WHTC were strongly correlated with engine operating conditions
and after-treatment device temperature. The higher particle number concentration during the ESC #7 to #10 mode was ascribed
to passive DPF regeneration and the thermal release of low volatile particles at high exhaust temperature conditions. The
detailed average particle number concentration equipped for golden DPF reached approximately 4.783E+11 #/kWh (weighted WHTC),
6.087E+10 #/kWh (WHSC), 4.596E+10 #/kWh (ETC), and 3.389E+12 #/kWh (ESC). Particle masses ranged from 0.0011 g/kWh (WHSC)
to 0.0031 g/kWh (ESC). The particle number concentration and mass reduction of DPF reached about 99%, except for an ESC with
a reduction of 95%. 相似文献
223.
W. K. Park S. D. Mun H. K. Lee G. E. Yang 《International Journal of Automotive Technology》2011,12(5):705-712
Compressed air can be used as an energy source for brake systems in medium-heavy and heavy-duty commercial vehicles. The moisture
in compressed air, which is due to high temperature and humidity, can be eliminated by using an air dryer. In this paper,
drying performance data for a cartridge were obtained and used to develop a drying performance program, to predict the moisture
and relative humidity in the air tanks of vehicles. The on-load time, off-load time, air flow, duty cycle, humidity and dew
point temperature were calculated according to air consumption. The validity of the program was verified, and it was shown
to be able to predict humidity changes in the air tank. The air tank capacity was increased from 100 to 130 to reduce the
duty cycle. Therefore, the regeneration rate decreased from 18% to 15%, but the dew point depression temperature (ΔT) remained
above 30°C. The duty cycle decreased from 50% to 43%, and the total operation time and power consumption of the air compressor
were reduced. In conclusion, fuel savings were obtained by changing the parameters to optimize the system. 相似文献