皮带机参考文献翻译

1、Dynamic characteristics of conveyor beltsHOU You-fu, MENG Qing-ruiSchool of Mechanical and Electrical Engineering, China University of Mining & Technology, Xuzhou, Jiangsu 221116, ChinaAbstract: The dynamic characteristics of a belt conveyor are determined to a large extent by the properties of

2、the belt. This paper describes experiments designed to establish the dynamic properties of belting material. The dynamic elastic modulus, viscous damping and rheological constants of the belt were measured. Several properties were studied as a function of the tensile loading on the belt. These inclu

3、ded longitudinal vibration, the natural vibration frequency in the transverse direction and the response to an impulse excitation. Vibration response was observed under several different excitation frequencies. Most of these properties have not been tested previously under conditions appropriate for

4、 the ISO/DP9856 standard. Two types of belt were tested, a steel reinforced belt and a fabric reinforced belt. The test equipment was built to provide data appropriate for designing belt conveyors. It was observed that the stress wave propagation speed increased with tensile load and that tensile lo

5、ad was the main factor influencing longitudinal vibrations.Key words: experimental investigation; dynamic characteristics; conveyor belt1 IntroductionBelt conveyors are, in most cases, the most cost-effective solution for handling bulk material mass flows over short and medium conveying distances. T

6、he belt is a key component of these conveyors and its dynamic characteristics determine the working performance to a great extent. At present,experimental research on the dynamic characteristics of conveyor belts is mainly concentrated on testing dynamic elastic modulus and viscous damping following

7、 the ISO/DP9856 standard. Little research on other dynamic parameters has been carried out.F. Langebrake et al. tested the breaking and splice strength of steel cord belts by using a large magnetic flux leakage tester1. Blazej et al. tested the tensile strength of the belt and the strength parameter

8、s of the rubber used for the adhesive-bond joint in splices by using a ZP40 testing machine2. Hou et al. reviewed the experimental research work on the dynamic characteristics of the belt published over the past two decades. They considered that the test piece used in the previous research work, bas

9、ed on the ISO/DP9856 standard, was too small (50 mm×300mm) to acquire reliable test data and suggested that a larger one should be adopted3. This paper describes the design and construction of an apparatus to investigate the dynamic characteristics of conveyor belting. Two types of belt, a fabr

10、ic belt and a steel cord belt, commonly used in coal mines were examined.2 Experimental2.1 ParametersThe main parameters studied by the experiments are:1) The dynamic performance parameters of the belt.2) The relationship between the stress wave propagation speed and the tension force on the belt.3)

11、 The dynamic response characteristics of the belt under different tension forces and exciting frequencies.4) The natural frequency of transverse vibration of the belt.2.2 MethodsThe first step is pretreatment of the test piece,which includes the measurement of its size and peeling two ends off for g

12、ripping. Then the test piece is installed on the test apparatus and kept in tension for 24 hours under a given tension force. Each individual test is repeated ten times and the average value is reported as the final test data.1) By using the shock response method, the stress wave propagation speed C

13、 was found and used tocalculate the dynamic elastic modulus Ed. Acceleration sensors were fixed at certain points to record the response signal. The stress wave propagation time t can be obtained by comparison of the signals of an impact force and the response signals picked up by the acceleration s

14、ensors. The stress wave propagation speed C can be calculated and Ed is then given by the equation , where is the density of the belt.2) The rheological constant , of the belt is obtained by analyzing the shock and vibration signals from displacement and acceleration sensors mounted at the same plac

15、e. The viscous damping ç, of the belt can be calculated by the relationship between ,çand E d .3) The response signals of the belt were tested under different tensile loads and exciting frequencies by mounting two displacement and two acceleration sensors at specified places and then analy

16、zing the interaction between the respective signals.4) The natural frequency for transverse vibration of the belt was identified by using a swept sine-wave excitation.2.3 ApparatusThe data from the experiments carried out in this paper are intended to assist in engineering applications.To acquire re

17、liable test data, the apparatus is built to simulate a real belt conveyor. The main features of the apparatus are as follows (see Fig. 1):1) The test piece is supported on carrying idlers,just as real conveyor belts are.2) The distance between two carrying idlers is approximately the same as in actu

18、al belt conveyors.3) The test piece is placed horizontally so that the sag is similar to that of actual belt conveyors.4) The test piece is tensioned by a screw nut.5) The longitudinal exciting force is applied by a vibration exciter. The signals were recorded with a TEAC MR 30 tape recorder and wer

19、e analyzed with an HP3562A dynamic signal analyzer. The test pieces included fabric belts and steel cord belts commonly used in coal mines. The cross sections of the belts are shown in Fig. 2. The design parameters of the belts are given in Table 1.3 Results3.1 Propagation speed of a stress wave alo

20、ng the beltThe stress wave propagation time can be obtained from the recorded impact force and response signals.The stress wave propagation speed can be calculated from the time. The results are shown in Table 2.The data in Table 2 show that the stress wave propagation speed varies with the belt typ

21、e and with tensile load. The speed increases nonlinearly with an increase in tension. Under lower tension the stress wave propagation speed increases more quickly. As the tension force increased above a threshold the stress wave propagation speed changed only slightly.The stress wave propagation spe

22、ed in the steel cord belts is greater than that of the fabric belts for a given tensile load.3.2 Dynamic parameters of the beltsThe dynamic elastic modulus of the belts can be calculated from . The results are shown in Table 3.The rheological constant of the belts can be found by analyzing the accel

23、eration and displacement from an impact; the results are shown in Table 4. Viscous damping coefficients can be calculated using the relationship between dynamic elastic modulus, the rheological constant and the viscous damping; the results are shown in Table 5 .From Tables 3, 4 and 5, it can be seen

24、 that the dynamic performance parameters of the belts vary over a large range as the tensile load changes. This indicates that because of viscoelastic behavior the dynamic characteristics of the belt vary under different boundary conditions.3.3 Natural frequency of transverse vibration of the beltTh

25、e natural, transverse, vibration frequency is that frequency where the response of the belt to a swept sine wave excitation is greatest. The results of swept sine wave tests are shown in Table 6.The data in Table 6 show that the natural frequency for transverse vibration in the two types of belt inc

26、reases slightly with an increase in the tensile force in a nonlinear way. The natural frequency for transverse vibration of the steel cord belt is greater than that of the fabric belt. According to belt transverse vibration theory, the steel cord belts are suitable for high speed belt conveyors.3.4

27、Response characteristics under different exciting frequenciesHarmonic excitation was applied to the belt at different frequencies (5 Hz, 10 Hz, 15 Hz, 20 Hz, 25 Hz and 30 Hz) under various tensile loadings. The longitudinalvibration of steel cord belts was measured.The results are shown in Figs. 3 a

28、nd 4.From Figs. 3 and 4, it can be seen that:1) The basic frequency of the longitudinal vibration of the belt is the same as the exciting frequency.2) Waveform in the time domain varies with the exciting frequency under the same tension force.Higher-frequency harmonics decrease gradually with an inc

29、rease of the exciting frequency. At an exciting frequency of 30 Hz the longitudinal vibration is close to a first harmonic waveform.3) By comparing the longitudinal vibration waveform shown in Fig. 3 with the one in Fig. 4 under the same exciting frequency, it can be seen that the higher-frequency h

30、armonic components are more obvious when the tension is greater. Different vibration waveforms have different effects on dynamic stress. Higher frequency harmonics intensify vibration of the belt and lead to increased dynamic stress. This is also the harmful effect from excessive tension.3.5 Respons

31、e to shock excitationThe vibration response of steel cord belts to an impulse excitation is shown in Fig. 5. It can be seen that the response decays exponentially, similar to the response characteristics of an elastic body. This indicates that the vibration characteristics of the belts are mainly de

32、termined by the elastic properties of the framework material of the belts.6 ConclusionsThe following conclusions can be drawn from the results of the experimental investigation:1) Stress wave propagation speed increases nonlinearly with an increase in tension in the belts.For the same tension force,

33、 the stress wave propagation speed of the steel cord belt is greater than that ofthe fabric belt.2) The dynamic performance parameters of the belts, including the dynamic elastic modulus, the rheological constant and the viscous damping, vary with tension force.3) The natural frequency of the transv

34、erse vibration in the belts slightly increases with the tensile load in a nonlinear way. The natural frequency of the transverse vibration in the steel cord belt is greater than that in the fabric belt.4) Tension force on the belt is the main factor that influences longitudinal vibration: The effect

35、 of excitation frequency is smaller. This indicates that more attention should be paid to controlling tensile loading in belt conveyor design.5) Steel cord belts have the same response characteristic to shock excitation as an elastic body. This indicates that the vibration characteristics of a belt

36、are mainly determined by the elastic properties of its framework material.AcknowledgementsThe authors would like to gratefully acknowledge Prof. Zhang Yong-zhong for his valuable contributions.References1 Langebrake F, Klein J, Gronau O. Non-destructive testing of steel-cord conveyor belts. Bulk Sol

37、ids Handling,1998, 18(4): 565569.2 Blazej R, Hardygora M. Modeling of shear stresses in multiply belt splices. Bulk Solids Handling, 2003, 23(4):234241.3 Hou Y F, Huang M, Zhang Y Z. Dynamic Performanceand Control Technology of Belt Conveyor. Beijing: Coal Industry Press, 2004. (In Chinese )输送带的动态特性

38、摘要：带式输送机的动态特性在很大程度上决定于输送带的特性。本论文叙述了输送带的动态性能的设计试验。输送带的动态弹塑性，粘性阻尼和流变参数已测定。包括纵向振动，横向振动的固有频率和受迫振动几类特性被作为输送带的拉力函数来研究。观察在几种不同的干扰频率下的振动响应。大多数特性以前并没有在ISO/DP9856标准下适当的测定。测试的是钢丝绳芯带和编织物带。建立测试装置为带式输送机的设计提供合理的参数。应力波传播速度随负荷的加载快速上升，这也是纵向振动的主要因素。关键词：实验研究；动态特性；输送带。1. 简介在大多数情况下带式输送机是解决大量块状材料的中短距离运输的高效率方案。带是输送机的关键部分，它

39、的动态特性在很大程度上决定了输送机的工作状况。目前，输送带的动态特性试验主要集中在检测基于ISO/DP9856标准的弹性系数和粘性阻尼。其它的动态特性则少有涉及。F. Langebrake及其他人用磁通量泄漏测试法检测了钢丝绳芯带的破坏和连接强度。Blazej及合作者用ZP40的测试仪器检测了用粘结剂粘合处橡胶接头的拉伸强度和强度参数。Hou等人评估了过去20年来公布的对动态特性的研究成果，认为之前的基于ISO/DP9856标准的研究所选的试件太小（50mm×300mm),难以获得可靠的实验结果，并建议应采用更大的试件。本论文叙述了一种输送带动态特性测试仪器的设计。并检测了两种形式的

40、输送带：编织物带和钢丝绳芯带。2.实验2.1参数 实验研究的主要参数：1) 带的动态性能参数；2) 应力波的传播速度与张紧力之间的关系；3) 在不同的张紧力和激振频率下的动态响应特性；4) 带横向振动的固有频率；2.2方法 第一步被测件的预处理，包括尺寸测量，剥去两端以便拉紧。然后将受测件置于测试仪器上，在给定张力下张紧24小时。每一单独的测试重复10次，并取平均值作为最终的实验数据。1) 用振动应答法测得应力波传输速度C，并用以计算动态弹性模量Ed，加速传感器安置在特定点来记录响应信号。应力波传播时间t可由压力和加速度传感器采集的信号对比获得；应力波传播速度C可以计算出，Ed可由公式得到是带

41、的密度2) 流变学的常数通过分析安装在同一地方的加速度和位移传感器采集的振动信号获得。带的粘性阻尼可由，Ed之间的关系来计算。3) 在特定位置安装位移和加速度传感器，在不同载荷和激振频率下测得信号并分析两者之间的相互关系。4) 通过正弦波的激励来分析横向振动的固有频率。2.3测试设备由本论文试验测得的数据可以用于辅助工程应用。为获得可靠的实验数据，测试设备尽量模拟真实的带式输送机。测试设备的主要部分如下(图 1 )。1) 试件如皮带机一样被放置在承载托辊上。2) 两承载托辊之间的距离与真正皮带机相似。3) 试件水平放置使垂度与真实皮带机上一致。4) 试件由螺母予以张紧。5) 纵向激励由激振器产生。由TEAC MR 30胶带记录数据，由HP3562A动态信号分析器分析试验数据