Variable IP method mainly measures the Percent Frequency Effect (PFE), and phase IP method mainly measures phase. They both aim at finding IP anomaly. However, only using PFE anomaly or single phase anomaly can′t dis...Variable IP method mainly measures the Percent Frequency Effect (PFE), and phase IP method mainly measures phase. They both aim at finding IP anomaly. However, only using PFE anomaly or single phase anomaly can′t distinguish IP body′s property. The authors put forward a new method——dualfrequency and multiparameter IP method, which can not only find anomaly of PFE and phase, but also provide the property information of IP anomaly resource. The authors also have invented the dualfrequency and multiparameter IP instrument. A lot of experiments and field work have been done. The results show that the instrument is valuable in distinguishing IP anomalies.展开更多
Typical multidisciplinary design optimization（MDO） has gradually been proposed to balance performances of lightweight, noise, vibration and harshness（NVH） and safety for instrument panel（IP） structure in the aut...Typical multidisciplinary design optimization（MDO） has gradually been proposed to balance performances of lightweight, noise, vibration and harshness（NVH） and safety for instrument panel（IP） structure in the automotive development. Nevertheless, plastic constitutive relation of Polypropylene（PP） under different strain rates, has not been taken into consideration in current reliability-based and collaborative IP MDO design. In this paper, based on tensile test under different strain rates, the constitutive relation of Polypropylene material is studied. Impact simulation tests for head and knee bolster are carried out to meet the regulation of FMVSS 201 and FMVSS 208, respectively. NVH analysis is performed to obtain mainly the natural frequencies and corresponding mode shapes, while the crashworthiness analysis is employed to examine the crash behavior of IP structure. With the consideration of lightweight, NVH, head and knee bolster impact performance, design of experiment（DOE）, response surface model（RSM）, and collaborative optimization（CO） are applied to realize the determined and reliability-based optimizations, respectively. Furthermore, based on multi-objective genetic algorithm（MOGA）, the optimal Pareto sets are completed to solve the multi-objective optimization（MOO） problem. The proposed research ensures the smoothness of Pareto set, enhances the ability of engineers to make a comprehensive decision about multi-objectives and choose the optimal design, and improves the quality and efficiency of MDO.展开更多
文摘Variable IP method mainly measures the Percent Frequency Effect (PFE), and phase IP method mainly measures phase. They both aim at finding IP anomaly. However, only using PFE anomaly or single phase anomaly can′t distinguish IP body′s property. The authors put forward a new method——dualfrequency and multiparameter IP method, which can not only find anomaly of PFE and phase, but also provide the property information of IP anomaly resource. The authors also have invented the dualfrequency and multiparameter IP instrument. A lot of experiments and field work have been done. The results show that the instrument is valuable in distinguishing IP anomalies.
基金supported by National Hi-tech Research and Development Program of China(863 Program, Grant No. 2007AA04Z132)National Natural Science Foundation of China(Grant No. 51175379)
文摘Typical multidisciplinary design optimization（MDO） has gradually been proposed to balance performances of lightweight, noise, vibration and harshness（NVH） and safety for instrument panel（IP） structure in the automotive development. Nevertheless, plastic constitutive relation of Polypropylene（PP） under different strain rates, has not been taken into consideration in current reliability-based and collaborative IP MDO design. In this paper, based on tensile test under different strain rates, the constitutive relation of Polypropylene material is studied. Impact simulation tests for head and knee bolster are carried out to meet the regulation of FMVSS 201 and FMVSS 208, respectively. NVH analysis is performed to obtain mainly the natural frequencies and corresponding mode shapes, while the crashworthiness analysis is employed to examine the crash behavior of IP structure. With the consideration of lightweight, NVH, head and knee bolster impact performance, design of experiment（DOE）, response surface model（RSM）, and collaborative optimization（CO） are applied to realize the determined and reliability-based optimizations, respectively. Furthermore, based on multi-objective genetic algorithm（MOGA）, the optimal Pareto sets are completed to solve the multi-objective optimization（MOO） problem. The proposed research ensures the smoothness of Pareto set, enhances the ability of engineers to make a comprehensive decision about multi-objectives and choose the optimal design, and improves the quality and efficiency of MDO.
