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Performance of an Elastic Polymer Foam Cushion in Attenuating Responses of Shipboard Standing-men to Vertical Ship Shock

WU Jing-bo;CHEN Yong;LI Zhao-jun; HUANG Jian-song;HUA Hong-xing

2011, 31 (4): 6-10. DOI: 10.3969/j.issn.1006-1355-2011.04.002

Abstract （1647）

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Protection of shipboard personnel from shock events induced by underwater explosion is very interesting to ship designers. In this study, the potential attenuation performance of an elastic polymer foam cushion inserted between standing-man and ship deck is investigated theoretically. An 8-DOF nonlinear lumped-parameter model is used to predict the standing-man’s biodynamic responses and injury potential. The cushion is modeled by a chain of masses separated by nonlinear springs and dampers in parallel to simulate the micro inertia, stiffness and rate-dependent effects exhibited by common polymer cellular materials. Two variables, kickoff speed (KS) ratio and deck reaction force (DRF) ratio corresponding to two types of typical injury potential of standing-men, are defined as evaluation parameters. The influence of critical buckling force level, material rate dependent effect as well as other design factors on the attenuation performance of the foam cushion is discussed in detail. Some general design rules are also presented.

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《Sound Quality Preference Evaluation and Objective Analysis for Vehicle，s Door Closing Sound》

WU Jing;CHEN Jian

2010, 30 (4): 119-122. DOI: 10.3969/j.issn.1006-1355.2010.04.031

Abstract （1849）

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The left front door closing sound samples at driver's left and right ears of 13 kinds of cars were collected as evaluation objects. Paired comparison method is applied for the subjective preference evaluation. Then, the characteristics of the sound samples which get high preference degree in the subjective evaluation test are studied and summarized. The main psychoacoustic parameters are calculated and the relationship between psychoacoustic parameters and subjective preference is analyzed.

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《Using Unbiased Estimation Method to Calculate Frequency Response Functions of Simply Supported Beams》

HUA Guangjun;WU Jingping;WU Yunxin

2009, 29 (5): 47-49. DOI: 10.3969/j.issn.1006-1355.2009.05.013

Abstract （3342）

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A multi-input and multi-output unbiased frequency response function (MMUFRF) estimation is put forward based on the feature that the mean of the incorrelate signal CSD (Cross Spectral Density) tends to zero. The proposed method is realized by MATLAB programming. Two-input and four-output test is carried on using the dynamic signal test systems and its MMUFRF is acquired by MATLAB program. Meanwhile, numerical simulation of the frequency response functions is made by means of finite element method. The simulation results show that the proposed MMUFRF can correctly estimate the frequency response functions of real structures.