车载机柜隔振系统道路试验

为分析车载机柜由于道路运输振动对物资产生的影响,在机柜和车厢之间安装钢丝绳隔振器,对运输物资垂向隔振效果进行测试。对机柜进行三种不同路面的道路运输试验。通过对试验数据进行研究分析发现,钢丝绳隔振器在机柜道路运输过程中具有明显的隔振效果。     

Creating Transport Vibration Simulation Profiles from Vehicle and Road Characteristics

It is today generally accepted that to carry‐out realistic transport simulation trials, field data must be acquired from vehicles travelling on the actual route(s) to be used for a particular distribution environment. This approach requires time, effort, access to data recording equipment as well as the necessary expertise to analyse the collected data. Often, this is out of reach of smaller operators who want a reasonable approximation without the time and expense. Currently, the only available option is the adoption of generic test spectra and levels that have been shown to be approximate representations of distribution environments. This paper discusses an alternative and practical method that uses some knowledge of the dynamic characteristics of various vehicle types along with an assessment of the types of roads (road roughness) to be encountered along a particular route. The method exploits the fact that the spectral characteristics (power spectral density) of road profiles are well known. The paper shows how this road surface elevation spectral function is combined with a numerical model of a particular vehicle type and speed to produce a target vibration power spectral density suitable for vibration test systems. One added benefit is that the method is capable of calculating the variations in root mean square levels of the response vibrations. This is presented as the root mean square distribution which, when coupled with the target power spectral density, can be used to synthesize realistic random vibrations that bear statistical similitude with real, field vibrations. Copyright © 2012 John Wiley & Sons, Ltd.     

A New Approach for Road‐Vehicle Vibration Simulation

A new approach for road‐vehicle vibration simulation is proposed and demonstrated feasible by testing with three express‐road vehicle‐vibration records, that is, record A, two‐wheel electric bicycle, 80% loaded, traveling on urban road; record B, median van, 50% loaded, traveling on urban road; and record C, minivan, 80% loaded, traveling on urban road too. This method decomposes the original signal into a series of approximate Gaussian‐vibration segments and a shock segment with high kurtosis by moving crest factor and one‐tenth peak‐value method. Simulate Gaussian‐distribution vibration one by one from the power spectral density (PSD) of each decomposed segments. The overall signal is simulated by concatenating of each decomposed Gaussian segment. The simulated signal has not only the same overall root‐mean‐square (RMS), duration as the original signal, but also has a similar PSD to the original signal, without incurring excessive acceleration levels. This allows an improved and more representative simulated input signal to be generated that can be use in the current generation of vibration table.     

Correlation Study Using Scuffing Damage to Investigate Improved Simulation Techniques for Packaging Vibration Testing

Vibration testing of packaging is a critical part of the distribution packaging analysis process. The accuracy of simulated vibration is important for packaging optimization. Because of this, several researchers have developed improved simulation methods to produce more realistic vibration tests. Correlation studies are required to verify these methods, ideally using actual packaged products in transit. Unfortunately, cost, time and complexity issues make carrying out studies with actual product difficult. This article uses a specially designed and proven test rig, which simulates the damage mechanism of scuffing, to carry out a correlation study. The study compares the level of damage produced when performing simulations using a range of improved techniques in comparison with the time‐history reproduction of a journey (used as a benchmark) and the established method using the average power density spectrum to create a Gaussian simulation signal. The level of scuffing damage produced varied between the different simulation methods, with the modulated root mean square (RMS) technique and the accelerated power density spectrum (with a time compression of 5 and a k equal to 2) best reproducing the level of damage observed from the benchmark time replication test. Copyright © 2012 John Wiley & Sons, Ltd.     

On the Use of Machine Learning to Detect Shocks in Road Vehicle Vibration Signals

The characterization of transportation hazards is paramount for protective packaging validation. It is used to estimate and simulate the loads and stresses occurring during transport that are essential to optimize packaging and ensure that products will resist the transportation environment with the minimum amount of protective material. Characterizing road transportation vibrations is rather complex because of the nature of the dynamic motion produced by vehicles. For instance, different levels of vibration are induced to freight depending on the vehicle speed and the road surface; which often results in non‐stationary random vibration. Road aberrations (such as cracks, potholes and speed bumps) also produce transient vibrations (shocks) that can damage products. Because shocks and random vibrations cannot be analysed with the same statistical tools, the shocks have to be separated from the underlying vibrations. Both of these dynamic loads have to be characterized separately because they have different damaging effects. This task is challenging because both types of vibration are recorded on a vehicle within the same vibration signal. This paper proposes to use machine learning to identify shocks present in acceleration signals measured on road vehicles. In this paper, a machine learning algorithm is trained to identify shocks buried within road vehicle vibration signals. These signals are artificially generated using non‐stationary random vibration and shock impulses that reproduce typical vehicle dynamic behaviour. The results show that the machine learning algorithm is considerably more accurate and reliable in identifying shocks than the more common approaches based on the crest factor. Copyright © 2016 John Wiley & Sons, Ltd.     

汽车室内道路模拟试验系统控制算法的研究

为了有效的进行汽车道路模拟试验，首先要通过系统识别获得整个试验系统的频响函数矩阵[FRF]，之后在目标信号模拟过程中获得满足试验要求的驱动信号。详细叙述了在系统识别过程中，对识别所得模型进行评判的相干函数法及预测法，和为获取更加准确模型而使用的模型平均法；以及为消除整个实验系统的非线性因素而在目标信号模拟过程中采用的迭代算法。最后，通过具体的试验对上述的控制算法进行了验证。     

基于实测路谱的振动环境分析与模拟方法研究

目的 开展无锡市内快递运输车辆的随机振动行为分析和缓冲衬垫损伤的实验室模拟再现,旨在指导包装系统随机振动加速试验,实现包装结构科学设计。方法 实地采集无锡市内中型厢式卡车运输过程中车厢不同位置的激励振动信号与包装系统响应信号;基于实测路谱处理得到实验室等比例加速、分频段加速测试谱;最后以多层瓦楞衬垫为研究对象,分别采用标准谱、等比例加速谱、分频段加速谱进行实验室加速模拟试验,对比实地运输中瓦楞衬垫损伤情况,验证各加速模拟测试方法的损伤等效性。结果 实测路谱与标准谱在形状与量级上均存在差异;基于实测路谱的等比例加速和分频段加速模拟试验衬垫损伤率误差分别为20.2%、10.1%,远小于标准谱加速模拟测试的误差（110.1%）;相较于等比例加速试验方法,分频段加速试验试验时间缩短了19min(29.7%)。结论 验证了基于实测路谱的分频段加速模拟测试的损伤等效性与快速性,该方法对实现防护包装的精准设计具有指导意义。     

Practical Considerations for Estimating Road Vehicle Frequency Response Functions from Response Data

This paper describes the application of a practical method to estimate the dynamic characteristics (frequency response function) of road vehicles using only on‐the‐road vertical vibration response data measured during nominally constant operating speeds. While several methods exist to estimate these dynamic characteristics, they are generally either inexact or prohibitively resource intensive. A review of two analytical approaches for estimating the frequency response function of road vehicles using only on‐the‐road vibration response data is presented. The first approach is based on the assumption that the road elevation profile takes the form of a specified spectral function. The second approach is based on the random decrement technique. A practical, step‐by‐step guide to undertaking on‐the‐road vehicle vibration measurements is included and provides numerous useful tips and considerations that should be taken into account. An investigation was also undertaken into the minimum record length (i.e. fraction of road length) required to accurately estimate the dynamic characteristics of road vehicles using a Monte Carlo simulation. From the study, it was found that a minimum road length of 10 – 15 km is sufficient to obtain a reasonably accurate estimate. Copyright © 2017 John Wiley & Sons, Ltd.     

Accelerated Random Vibration Testing of Transport Packaging System Based on Acceleration PSD

Transport packaging of products is a complex structural system, having a variety of modes for vibration damage failure under the action of random vibration in logistics. In order to evaluate the packaging performance effectively, the accelerated random vibration testing becomes one of important tools. This paper develops a more general and practical method for accelerated random vibration testing of transport packaging in the framework of linear random vibration of discrete packaged product. The suggested method is based on the response acceleration power spectral density (PSD) of component which is easy to measure, and suitable for the different fatigue models more than Basquin fatigue model. It is confirmed by the experiments of a packaged desk computer that exerted two types of acceleration PSDs. Copyright © 2017 John Wiley & Sons, Ltd.     

Issues with Combining Road Elevation Spectral Models and Vehicle Vibration Response to Estimate Vehicle Dynamic Characteristics

The research presented in this paper focuses on issues associated with the development of an experimental technique to estimate the dynamic characteristics of wheeled vehicles (namely, the frequency response function) using only in‐service response data. To validate the approach and eliminate complexities associated with multi‐wheel vehicles, a single‐wheeled prototype vehicle was designed and commissioned. The vertical vibration acceleration of the prototype vehicle's sprung mass was measured during normal operation. The power spectral density function was computed and used to estimate the frequency response function of the vehicle. A number of experiments using various configurations of the single‐wheeled prototype vehicle were undertaken, along with a series of vibration table experiments to provide a comparison with the estimated frequency response functions. The results show that the best estimate of the frequency response function using the vehicle response data provides reasonable agreement with the measured laboratory experiments when the value of the slope of the spectral function is not set to the value suggested by the International Organisation for Standardisation. Another technique was further developed to estimate the value of the pavement spectral slope using only in‐service response data; however, this technique does not yield consistent and accurate estimates. Interestingly, the main resonance of the vehicle is in agreement between the vibration table and response data around the sprung mass of all three vehicle configurations when inspected using linear scales (regardless of the variation in the spectral shape of the excitation), although the additional modes (including the unsprung mass) differs for all vehicles. Copyright © 2014 John Wiley & Sons, Ltd.     

The Statistical Characteristics of Maxima of Contact Force in Stacked Packaging Units under Random Vibration

Stacked packaging units are the major form when transporting packaged products. In these stacked packaging units, the maxima of contact force between boxes are closely related with fatigue, the main failure form of packaged products during transportation, which can be simulated by random vibration. Therefore, this paper proposes a probability density function (PDF) of maxima for stationary Gaussian random signal with non‐zero mean and non‐unit variance to study the statistical characteristics of the maxima of contact force in three‐layer stacked packaging units, which is of vital importance to the fatigue evaluation. The proposed PDF of maxima is controlled by three parameters: spectral width parameter ? , mean value μ_x and variance σ_x . These three parameters are obtained respectively under three different impact factors, namely, constraint, acceleration excitation and location of contact surface. Power spectrum density (PSD) of contact force and PSDs' Q factors are also calculated. Relations and variations of the three parameters of PDF of maxima, PSD and PSD's Q factor under different impact factors are discussed in detail. It is found that the system of the three‐layer stacked units with a wide‐band excitation (? → 1) as input and contact force (?< 1) as output can be regarded as a relatively narrow band system. And the proposed PDF of maxima proves to be an effective method to investigate the statistical characteristics of the maxima of contact force between boxes in the stacked packaging units. Copyright © 2017 John Wiley & Sons, Ltd.     

高斯与非高斯随机振动对洗护产品包装的影响

目的 研究高斯激振力和非高斯激振力的随机振动对商品包装的影响差异,提供随机振动试验方法和参数,并对商品运输包装设计方案提供优化建议。方法 利用科学计量方法研究随机振动技术的发展态势。通过增大峭度的方法进行非高斯激振模拟随机振动试验。研究随机振动强度通过功率谱密度和疲劳损伤的表达,以及随机振动试验时间与疲劳损伤的表达关系。结果 电商渠道销售通过快递配送的洗洁精商品包裹优先采用ISTA 3A—2018 Packaged-Products for Parcel Delivery System Shipment 70 kg(150 lb) or less。使用Over-The-Road Trailer图谱和Pick-up and Delivery Vehicle图谱进行随机振动试验,通过加载峭度进行加速模拟试验和加强模拟试验。结论 在洗洁精商品包裹加载峭度为5、7、9条件下,能够复现实际配送中商品的货损。基于试验结果提出的包装设计修改方案在加强模拟试验条件下可以实现商品防护的功能。全渠道供应链配送商品包裹应采用高效、科学的实验室测试方法,为运输包装设计和验证提供方法和数据。     

基于ANSYS的多轴汽车振动响应分析

为了高效预测路面不平度输入下多轴汽车悬挂质量某一位置处的振动响应特性,依据多体动力学理论,利用ANSYS仿真工具建立多轴汽车的七自由度动力学仿真模型。在整车发动机定转速的试验基础上,运用理论分析、仿真计算相结合的方法,根据建立的模型对整车进行仿真分析与研究。结果表明仿真计算结果与试验结果基本一致,可见,所提出的动力学模型和分析方法具有较好的可信度。仿真结果表明：在路面不平度输入下,影响悬挂质量[-]6 m～[-]4 m处的加速度响应以第1阶固有频率为主;而在[-]2 m～4 m处以第2阶固有频率为主,尤其是在悬挂质量的后端;第2阶固有频率是影响多轴汽车加速度振动响应特性的最主要的因素,改善该多轴汽车的平顺性需把研究重点放在多轴汽车的第三四车轴的悬架系统上。     

运输包装系统随机振动频域分析

为了研究包装件在实际流通环境振动特性下的振动规律,以车辆、包装件构成的六自由度运输包装系统为基础,构建了在以白噪声为输入的路面不平激励下的振动模型,建立了路面不平激励的数学模型、运输车辆以及包装件的动力学模型。借助Matlab/Simulink仿真技术,对运输包装系统随机振动进行了频域分析,得到了内装产品及易损零件随机振动加速度响应的幅值频谱和功率谱密度。仿真结果表明了随机振动强弱程度与频率的关系,全面反映了随机振动规律,为缓冲包装设计提供了理论依据。     

军用车辆器材托盘基数化组套包装研究

分析了车辆器材托盘基数化组套包装的目的及意义,在此基础上提出了托盘基数化组套包装的实现方法及步骤,并研究了托盘基数化组套方法,对开展托盘基数化组套包装工作具有一定的指导意义。     

基于混沌振动力学的压路机工程

为将混沌振动力学的理论研究转化为压路机工程的新技术成果,研制了三种混沌振动压路机(0．75t,10t,14t),并进行了振动测试、数值仿真与压实试验,证明混沌振动压路机比普通振动压路机提高工效12．2％。其中,14t重型混沌振动压路机已用于我国西部高速公路开发。     

Monitoring and simulating non‐stationary vibrations for package optimization

This paper introduces a new method to analyse and simulate vibrations of transport vehicles. The method pays particular attention to the non‐stationary nature of vibrations, especially during road transport. The limitations of current methods used for analysing and simulating vehicle vibrations are demonstrated. The paper shows how the Hilbert transform can be used to compute the vibration intensity and offers substantial data reduction advantages. It is shown how statistical characteristics of the vibration intensity can be combined with spectral characteristics to enable more realistic simulations of transport vibrations. Finally, it is shown how the processed data is well suited for use with modern telemetry techniques integrated with web browser technologies. Copyright © 2000 John Wiley & Sons, Ltd.     

商用车汽车座椅振动传递特性研究

对商用车中常用的机械减振座椅的垂直方向传递特性进行研究,通过液压伺服振动试验台测量了座椅的传递率。通过建立座椅多体动力学模型,在验证模型的基础上,应用正交试验方法,找到对系统影响较大的因素,改进了座椅的减振性能。     

列车垂向振动的半主动简谐隔振研究

依据拉格郎日方程,建立六自由度列车半主动隔振系统的垂向振动模型;应用MATLAB/SIMULINK仿真模块构造列车半主动隔振系统仿真模型,对列车进行时域分析。在轨道具有简谐输入的情况下对列车的隔振性能（如隔振位移、隔振传递率等）进行了计算分析,讨论了弹簧刚度、阻尼、车速、激励的波长等对隔振性能的影响。通过研究可得列车系统采用半主动开关阻尼器,确实能够改善系统的隔振性能。     

一种路面曲面不平度的数字生成方法

将路面看成一个包含多种空间频率成份的高低不平曲面，而不是一条沿路面延伸方向的曲线。研究了采用数字仿真生成模拟路面曲面的方法，代替了常用的单一波形描述法。在路面曲面仿真模型中，采用基于布朗运动过程的半球面形状来描述真实路面的起伏情况，数字仿真分析表明采用该模型生成的路面曲面，其数字特征符合国际标准协会的规定，能真实的反映出路面的起伏状况。