A New Approach for Road‐Vehicle Vibration Simulation

2018

Self Cite

In general, existing testing methods for packaging design employ Gaussian distributions to represent vibration induced by road profiles. However, the actual road vehicle vibration is non‐Gaussian. The key limitation is that the simulated Gaussian vibration cannot reconstruct the shock events buried in the vibration, which will result in inaccurate reliability evaluation of cushion packaging. A new simulation technique called shock extraction has been proposed and validated in our earlier study. This article is a further study of our previous research. The shock extraction method has been compared with other three representative simulation methods including the single‐level PSD, three‐way split spectral, and wavelet decomposition in terms of simulation effect. Signal simulated by the shock extraction method possesses the same vibration intensity, duration, approximate statistical characteristics, and PSD plots with the original signal. The results show that the simulation effect of the shock extraction method is the best, and the worst is the single‐level PSD. The wavelet decomposition and three‐way split spectral are somewhere in the middle.

Section: Introductionmentioning

confidence: 99%

“…Griffiths et al investigated the correlation of several improved simulation techniques based on this scuff measuring device. Furthermore, a new simulation method called shock extraction for short has been proposed and validated in our earlier research …”

Section: Introductionmentioning

confidence: 99%

Comparison study on simulation effect of improved simulation methods for packaging random vibration test

Zhou

2018

Self Cite

“… Simulation of road vibrationThe excitation from vibrator is Gaussian stationary, which is different from the road vibrations. To accurately achieve optimized packaging, it is very necessary to improve accuracy of the simulation Accelerated random vibration testTo evaluate the fatigue damage, the tests using the PSD from standards or road vibration data are carried out, which usually costs a long time.…”

Section: Introductionmentioning

confidence: 99%

“…The excitation from vibrator is Gaussian stationary, which is different from the road vibrations. To accurately achieve optimized packaging, it is very necessary to improve accuracy of the simulation …”

Section: Introductionmentioning

confidence: 99%

Influence of jumping phenomenon on response of package under random vibration

Fang

2018

Self Cite

Because asymmetric contact is characteristic of the package surface, jumping phenomenon may happen under strong random vibration. To study the influence of jumping phenomenon on package response, a piecewise linear random vibration model is established. By applying Fokker‐Planck‐Kolmogorov (FPK) equation method, distribution of displacement composed of Gaussian distribution and exponential distribution is obtained. After that, distribution of maxima of displacement composed of Rayleigh distribution and exponential distribution is obtained. The proportion of time taken by loss of contact in a single cycle is studied under different peak of displacements. When the peak of displacement is from 1 to 3, the period is from 2π to 2.56π, and proportion of time taken by loss of contact is from 0% to near 50%. By applying the relation between peak of displacement and contact force, distribution of maxima of contact force can be obtained as translational Rayleigh distribution, which is also proved by numerical simulation and experiment respectively. Moreover, by numerical simulation, distribution of acceleration and time history of modified displacement are obtained. It is found that when Root‐Mean‐Square (RMS) value of displacement signal increases, probability of loss of contact becomes greater, and the time cost by the same number of cycles will be prolonged. By experiment, distribution of acceleration and acceleration Power Spectral Density (PSD) are obtained. It is found that when random excitation increases, the probability of −g increases and the frequency corresponding to peak of acceleration PSD declines. It indicates that the loss of contact causes the decline of the central frequency.

“…On the study of the dynamic behaviour of goods and road vibration, Wang and Fang and Rouillard et al give the dynamic performance of stacked packaging units under random vibration. Methods of road‐vehicle vibration simulation and vibration behaviour during transportation are studied …”

Section: Introductionmentioning

confidence: 99%

Investigation on vibration scuffing life curves

Rouillard

2018

Self Cite

The printing images on products and packaging play an important role in increasing the business value, adding artistic quality, and sending information. During transportation, scuffing of the printing images will emerge due to vibrations and impacts induced by rough roads and vehicles. This paper investigates experimentally the vibration scuffing through an ink transfer device. The scuffing value–time curves are obtained. Then the scuffing life curves Grms,e‐Na,e based on excitation acceleration root‐mean‐square (RMS) and Grms,r‐Na,r based on relative acceleration RMS are developed. Both Basquin‐type and exponential‐type curves may be applied to describe the scuffing life in this case. The excitation frequency width covering the resonance frequency has a significant effect on the scuffing life curve Grms,e‐Na,e based on excitation acceleration RMS; however, it is not obvious on the scuffing life curve Grms,r‐Na,r based on relative acceleration RMS. The vibration system filters out the broadband excitation vibration frequencies away from the resonance zone and makes the relative acceleration signal a narrow one. The scuffing life curve in the resonance scuffing state is very different from that in the nonresonance scuffing state, and they should be distinguished in practical application. The scuffing life equations and curves obtained in this paper may provide a reference to the further research on packaging scuffing and its test evaluation and accelerated vibration test in laboratory.