Paul J. Munzenberger’s research while affiliated with University of Newcastle Australia and other places

In this chapter, simulation methods applied to belt conveyor design and troubleshooting are presented. Finite and Discrete Element Methods are described to calculate the static and dynamic belt tensions within the conveyor belt during starting, steady‐state running, and stopping, with the aim to improve performance and reliability of the system. Similarly, the Finite Element Method is applied to the design of critical conveyor components, while the Discrete Element Method and Computational Fluid Dynamics are presented to assist in plant troubleshooting and provide insight into maintenance issues experienced due to complex dynamic interactions.

The University of Newcastle has designed and built a large test facility to measure the combined indentation rolling resistance and belt flexure resistance. This test facility allows tests to be conducted on a full-sized conveyor belt over a range of tensions and belt velocities and is designed in accordance with an Australian standard [1]. The test facility applies tension to the conveyor belt using two hydraulic rams and applies a vertical load by deflecting the conveyor belt over two adjustable height rolls via hold down rolls set apart at equal distances to the measurement idler roll. Experimental results from the University of Newcastle test facility include measurements of both indentation rolling resistance and belt flexure resistance in combination. A way is needed to separate the indentation rolling resistance and belt flexure resistance into their individual components. One approach is to predict the belt flexure resistance component and validate the prediction by measuring the indentation rolling resistance using the DIN22123 [2] experimental method. In this experimental method the belt is tensioned by two hydraulic rams and the vertical load is applied with an idler roll placed above the measurement idler roll. The setup has the advantage of applying the vertical load without flexing the conveyor belt. The results from the DIN standard will provide indentation rolling resistance individually, and this can be compared to the Australian Standard [1] of measuring the combined indentation rolling resistance and belt flexure resistance. Two methods of measuring indentation rolling resistance and belt flexure resistance components will be discussed in this paper, analytical models will be presented and, in combination with laboratory test data, trends identified to reduce the motion resistance.

Rubber stress relaxation models are the main material input data for numerical and analytical conveyor belt indentation rolling resistance calculations. Stress relaxation data for rubbers, such as those used in the construction of conveyor belts, are difficult to measure directly due to their fast relaxation times and, as such, they are usually derived via a dynamic mechanical analysis; unfortunately, relaxation data for the strain levels reached in conveyor belting cannot be produced with typical dynamic mechanical analysis machines. This paper utilizes high strain level data produced on a high capacity dynamic mechanical analysis machine and compares the indentation rolling resistance predictions derived from the measured high strain relaxation moduli with other high strain relaxation moduli extrapolated from low strain level measurements that can be measured on dynamic mechanical analysers with smaller capacities. Jonker’s equation and a two dimensional finite element analysis model are used to compare the different sets of relaxation moduli and these are compared with results from large scale indentation rolling resistance experiments.

The indentation rolling resistance of conveyor belts is an important design consideration for long belt conveyors and can also be important for heavily loaded belt conveyors. Indentation rolling resistance is dependent on the properties of the conveyor belt, including the carcass and bottom cover as well as properties of the belt conveyor including induced loads, belt speed, ambient temperature and idler roll diameter. A purpose built laboratory test facility is described to measure the indentation rolling resistance of conveyor belts. The test facility is designed to accept both fabric and steel cord belts and test over a range of typical operating parameters and conditions. Results are presented for a range of test parameters, including; load, belt speed, idler roll diameter, ambient temperature and bottom cover compound. Application of the test data to conveyor design is also presented with the aim being to show how the test facility can be used to improve the accuracy of conveyor belt tension calculations by more accurately evaluating the performance of different rubber compounds and belt constructions.

The University of Newcastle has undertaken a systematic research program to identify, model and measure key design elements to reduce the energy consumption of belt conveyors. Research outcomes include the development of theoretical models to accurately predict the main resistances of belt conveyors, in parallel with developing extensive test facilities to verify the new models and to provide industry with data that can be used directly in the design process. This paper discusses the application of these models and test results for conveyor design, demonstrating the advantages of informed component selection to not only reduce energy consumption, but also total cost of ownership. In particular, the combination of design parameters is discussed in relation to the rotating resistance of idler rollers, conveyor belt indentation rolling resistance and conveyor belt and bulk material flexure resistance. Through a combination of theoretical models and measured data, trends are identified to assist in the design of energy efficient belt conveyor systems.

This article discusses how determining the viscoelastic properties of the cover material of a conveyor belt, using different rheological test modes, can result in significant differences in properties for the same material and testing conditions. The viscoelastic properties are applied to two mathematical models used to predict and compare the indentation rolling resistance performance of two rubber compounds. This article demonstrates how inaccuracies in the testing of the viscoelastic properties could result in a material with higher indentation rolling resistance properties being selected for a conveying system, making the power consumption of the system larger than necessary. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40755.

There are many analytical and numerical models that are designed to predict the indentation rolling resistance of conveyor belts that have as their main input the relaxation properties of the physical rubber that is being modelled. Relaxation data for rubbers such as those used in the construction of conveyor belts are difficult to obtain directly and must be derived by other means. This paper examines a selection of different processes for producing relaxation data and examines the effects of the resulting relaxation data on the indentation rolling resistance predictions from a numerical finite element model.

This paper provides details of the development and application of a viscoelastic finite element analysis of the indentation rolling resistance problem of a conveyor belt moving over an idler roll. The finite element analysis (FEA) is performed using the commercial FEA software Strand7. The analysis presented models the viscoelastic rolling contact problem as the bottom cover of the conveyor belt is indented due to the weight of the belt and bulk material. The analysis predicts an asymmetric pressure distribution within the indentation zone due to the viscoelastic properties of the rubber cover, from which the indentation rolling resistance factor is calculated.