scholarly journals The Shock Characteristics of Tilted Support Spring Packaging System with Critical Components

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
An-Jun Chen

The nonlinear dynamical equations of tilted support spring packaging system with critical components were obtained under the action of half-sine pulse. To evaluate the shock characteristics of the critical components, a new concept of three-dimensional shock response spectrum was proposed. The ratio of the maximum shock response acceleration of the critical components to the peak pulse acceleration, the dimensionless pulse duration, and the frequency parameter ratio of system or the angle of tilted support spring system were three basic parameters of the three-dimensional shock response spectrum. Based on the numerical results, the effects of the peak pulse acceleration, the angle of the tilted support spring, the frequency parameter ratio, and the mass ratio on the shock response spectrum were discussed. It is shown that the effects of the angle of the tilted support spring and the frequency ratio on the shock response spectrum are particularly noticeable, increasing frequency parameter ratio of the system can obviously decrease the maximum shock response acceleration of the critical components, and the peak of the shock response of the critical components can be decreased at low frequency ratio by increasing mass ratio.

2011 ◽  
Vol 18 (3) ◽  
pp. 437-445 ◽  
Author(s):  
Jun Wang ◽  
Zhi-Wei Wang ◽  
Li-Xin Lu ◽  
Yong Zhu ◽  
Yong-Guang Wang

To evaluate the shock characteristics of critical component for a nonlinear packaging system, a new concept of three-dimensional shock spectrum was proposed. Three key coordinate parameters, such as the nondimensional pulse duration, the frequency parameter ratio and the ratio of the maximum response acceleration to the peak pulse acceleration, were governed in a novel dynamical mathematical model. It is shown that the shock response of critical component is weakened owning to the decrease in the defined system parameter. Furthermore, at low frequency parameter ratio, the enhancement of the damping ratio of the critical component leads to the decrease in the peak of the shock response, which can also be reduced by the increase in damping ratio of cushioning pad at both lower and higher frequency parameter ratios. The discussion and analysis provide some insights into the design of cushioning packaging as well.


1995 ◽  
Vol 38 (6) ◽  
pp. 13-17
Author(s):  
M. Hine

The excessive overtest associated with the swept sine vibration test method was measured quantitatively using the index of conservatism and the associated overtest factor for a dynamic mass model of a typical spacecraft component. The response to a fixed amplitude sine sweep test was compared with the flight transient vibration environment for sweep rates of 2, 4, and 6 octaves/min and 300 Hz/min. A response-limited test was also conducted at 6 octaves/min. The conservatism was measured using several characterizations; namely: number of peaks exceeding, ranked peaks, shock response spectrum, shock intensity, three-dimensional shock response spectrum, and ranked peaks. Overtest factors exceeding an order of magnitude were measured for the test response with the number of peaks exceeding and the three-dimensional shock response spectrum.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Ningning Duan ◽  
Meng Hao ◽  
Anjun Chen

Dimensionless nonlinear dynamical equations of a tilted support spring nonlinear packaging system with critical components were obtained under a rectangular pulse. To evaluate the damage characteristics of shocks to packaged products with critical components, a concept of the damage boundary surface was presented and applied to a titled support spring system, with the dimensionless critical acceleration of the system, the dimensionless critical velocity, and the frequency parameter ratio of the system taken as the three basic parameters. Based on the numerical results, the effects of the frequency parameter ratio, the mass ratio, the dimensionless peak pulse acceleration, the angle of the system, and the damping ratio on the damage boundary surface of critical components were discussed. It was demonstrated that with the increase of the frequency parameter ratio, the decrease of the angle, and/or the increase of the mass ratio, the safety zone of critical components can be broadened, and increasing the dimensionless peak pulse acceleration or the damping ratio may lead to a decrease of the damage zone for critical components. The results may lead to a thorough understanding of the design principles for the tilted support spring nonlinear system.


2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Ningning Duan ◽  
Shuang Song ◽  
Anjun Chen

Dimensionless nonlinear dynamical equations of a tilted support spring nonlinear system with critical components were obtained under the action of a rectangular pulse, and the numerical results of the shock response were studied using Runge-Kutta method. To evaluate the dynamic characteristics of critical components, a new concept of three-dimensional shock response spectra was proposed, where the ratio of the maximum shock response acceleration of critical components to the peak pulse acceleration, the pulse duration, and the frequency ratio were three basic parameters of three-dimensional shock response spectra. Based on the numerical results, the effects of the angle, the peak pulse acceleration, the mass ratio, the frequency ratio, and the pulse duration on the shock response spectra were discussed.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Jing Qian ◽  
Heping Cai ◽  
Weiwei Ma ◽  
Zhiwei Hao

Both analyses of the damage boundary and shock response spectrum (RSR) are the basis for the development of the protective packaging system. The shock analysis through lab test and numerical simulation found that the root cause of packaging failure was due to the stress of the critical component beyond the yield limit of the material. Lab shock test data showed that the packaging design based on the damage boundary is conservative, and the RSR could be helpful and provide support to develop more effective packaging system. Furthermore, numerical simulation can accurately analyze the component and the entire product packaging system in great detail.


2011 ◽  
Vol 66-68 ◽  
pp. 245-249
Author(s):  
Jiu Hong Jiang ◽  
Jun Wang

The shock characteristics of a cubic nonlinear stacking packaging system were investigated under the action of half-sine acceleration pulse. The dynamical model of the system was developed, and the numerical results of the dynamical equations were obtained. Based on the results, a new concept of combined shock response spectrum was proposed to describe the shock characteristics of cubic stacking packaging system, focusing more on the maximum of the peak response acceleration of all products at all sensitive frequency since the damage of stacking packaging system occurs when any of the products was damaged. And it’s found that the combined shock spectrum is always made up of the shock spectrum of the bottom layer at lower dimensionless pulse duration and the shock spectrum of the top layer at higher dimensionless pulse duration. Then, the effect of the peak pulse acceleration, the defined system parameter, the damping ratio of cushioning pad in addition to the number of stacking layers on the combined shock spectrum of the system was discussed. It’s shown that all of their effect are noticeable. The results lead to some insights into the design of cushioning packaging.


2021 ◽  
Vol 9 (3) ◽  
pp. 349
Author(s):  
Andrii Sulym ◽  
Pavlo Khozia ◽  
Eduard Tretiak ◽  
Václav Píštěk ◽  
Oleksij Fomin ◽  
...  

This article deals with the method of computer-aided studies of the results of tank container impact tests to confirm the ability of portable tanks and multi-element gas containers to withstand the impact in the longitudinal direction on a specially equipped test rig or using a railway flat car by impacting a flat car with a striking car, in compliance with the requirements of the UN Navigation Rules and Regulations. It is shown that the main assessed characteristic of the UN requirements is the spectrum of the shock response (accelerations) for the interval natural frequencies of the shock pulse. The calculation of the points of the shock response spectrum curve based on the test results is reproduced in four stages. A test configuration of the impact testing of the railway flat car with a tank container is presented, and the impact is performed in such a way that, under a single impact, the shock spectrum curve obtained during the tests for both fittings subjected to impact repeats or exceeds the minimum shock spectrum curve for all frequencies in the range of 2 Hz to 100 Hz. Formulas for determining the relative displacements and accelerations for the interval natural frequencies of the shock wave are given. The research results are presented in graphical form, indicating that the experimental values of the shock response spectrum exceed the minimum permissible values; the equation of the experimental curve of the shock response spectrum in the frequency range 0–100 Hz is described by power-law dependence. The coefficients of the equation were determined by the statistical method of maximum likelihood with the determination factor being 0.897, which is a satisfactory value; a comparative analysis showed that the experimental curve of the impact response spectrum in the frequency range 0–100 Hz exceeds the normalized curve, which confirms compliance with regulatory requirements. A new test configuration is proposed using a tank car with a bulk liquid, the processes in which upon impact differ significantly from other freight wagons under longitudinal impact loads of the tank container. The hydraulic impact resulting from the impact on the tank container and the platform creates an overturning moment that causes the rear fittings to be unloaded.


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