Guoan Chen

Effect of load and sliding velocity on tribological behaviors of aramid fiber reinforced PA1010 composites

– The purpose of this paper is to present and analyze the effect of applied load and sliding velocity on the tribological behaviors of aramid fiber (AF) reinforced PA1010 which can be a potential material for transmission components., – The PA1010 composites with different content of AF are prepared and the tribology experiments are conducted on a block‐on‐ring wear tester under different experiment conditions. The wear mechanism of the composite is examined by means of scanning electron microscopy., – The addition of AF decreased the friction coefficient of PA1010 and increased its wear resistance. For optimal tribological properties 5∼15 wt% AF is preferred, while the wear resistance is best at 15 wt%. The friction coefficient decreased with increasing load and sliding velocity, but it is more sensitive to load. The main wear mechanism is abrasive wear at relatively low load and sliding velocity. With the increasing of load, the adhesive wear occurs in the matrix, meanwhile obvious fibrillation and layer peeling are observed on the fiber. When the sliding velocity increases, thermal adhesion and fiber debonding is the dominant mechanism., – PA1010 is a useful material for the alternative material of transmission components in industry., – PA1010 composite is prepared with a new kind of AF fiber and the tribology experiments have been carried out emphasizing on the variation of experiment conditions. The results could be useful for the material engineers.

Forward kinematics analysis and experimental validation of a four-cable-driven under-constrained parallel mechanism

Taking the sinking winch mechanism as prototype, this paper studies the forward kinematics problem of a four-cable-driven under-constrained parallel mechanism. The tension states (slackness and tautness) and properties of the cables are incorporated into the forward kinematics model. We propose a new algorithm (named traversal algorithm) to solve the tensions in cables and the pose of platform, under the condition that only the lengths of four cables are known. The simulation and experimental results on forward kinematics demonstrate the effectiveness and correctness of the model and the traversal algorithm. The results of this paper can be used to evaluate the effect of the unequal cables’ lengths to the tension distribution of cables and pose of the platform for sinking winch mechanism.

Computer-aided modeling of wire ropes bent over a sheave

Abstract In the paper, two methods for building a 3-dimensional geometry of a wire rope bent over a sheave in Proe™ are presented. In order to obtain the centroidal axes of the wires, the first method is associated with deriving their coordinate equations based on the Serret–Frenet frame and the second method is characterized by using the ‘Variable Section Sweep’ tool in Proe™ to generate a helically twisting surface around the centroidal axis of the king wire or a strand with the two boundary curves being the centroidal axes of two double or triple helical wires. Finally, both methods use the ‘Variable Section Sweep’ tool to generate the geometries of the wires. The two methods can be applied to any helical-strand wire rope.