Design and evaluation of a shock load resistant dynamic chain plate

Abstract: Conveyor chains are often subject to repetitive shock loads during normal operations. This can cause accelerated wear in the chain leading to premature chain replacementor chain failure (Otoshi, 1997, p. 4). In this thesis a new approach for reducingshock load related wear in conveyor chains is proposed. The scope and objective ofthis project is to investigate the shock load phenomenon and develop a dynamic pinlink chain plate. A study into chain wear and shock loads of chain driven conveyorswas made to identify problem areas. Additionally, a Simulink model was created tosimulate the influence of shock loads on conveyor chains. Common wear as a result ofshock loads are identified as pin failure, bushing failure, scuffing, chain plate failure,fatigue and chain elongation, (Otoshi, 1997, p. 76-78). Nine concepts were drafted and evaluated using methods described in (Ulrich &Eppinger, 2016). The concepts were simulated using Finite Element Analysis (FEA)and two concept iterations, Concept B v.3 and Concept C v.3, were manufacturedfor static tensile tests using two different setups and Digital Image Correlation (DIC)system for additional strain measuring. The breaking load for Concept B v.3 andConcept C v.3 is 105 and 70 kN respectively. The approximate yield strength ofConcept B v.3 is 11 kN and 40 kN for Concept C v.3. The Fatigue limit was estimatedto 10 kN for Concept B v.3 and 20 kN for Concept C v.3. A nonlinear FEA for Concept C v.3 and Concept B v.3 provided additional insightinto the behaviour of the pin link chain plates during high stress concentrations. While neither the linear static nor nonlinear static analyses managed to accuratelypredict the behaviour of Concept B v.3, the simulated results of Concept C v.3 werein line with the observed tensile tests. From the results it is concluded that a dynamic chain plate in the form of ConceptC v.3 has the potential to reduce the magnitude of the force in the chain imposedby shock loads, while still following the current ISO standard for conveyor chains. The resulting design proposition provides an easy to manufacture high strength chainplate with increased elastic properties.Future work should be focused on determining the fatigue life and shock load resistanceof the developed chain plate. It is recommended that material selection is focused onwear and fatigue resistant materials and that both simulated and physical dynamictesting is performed.