NUMERICAL AND FINITE ELEMENT CONTACT TEMPERATURE ANALYSIS OF FRICTION MATERIAL ’S TYPE EFFECT ON A THERMAL TRANSIENT BEHAVIOR OF A SINGLE-DISC DRY CLUTCH

The sliding period is considered a critical period in the lifetime of friction clutches, because most failures occur during this period. High temperatures due to sliding velocity will appear on the contacting surfaces of the friction clutch system (e.g., in single -disc clutch are pressure plate, clutch discs and flywheel). The finite element technique has been developed to investigate the effect of the type of friction material (material properties) on the transient thermoelastic behaviour of a single-disc dry clutch. Two types of friction materials are used in this work: organic and sintered friction materials. Axisymmetric models are developed to simulate a friction clutch system (single disc with two effective sides). The results represent the comparisons between organic and sintered friction discs, behaviours during slipping periods in clutches.

Study of Contact Temperature in Polishing Surfaces

Based on a three-body micro-contact mechanism and contact temperature theory, a micro-contact temperature model was developed to investigate the effect of particle size, particle density, and rotational speed on temperature rise between particles and workpieces. The experiments with different particle sizes and rotational speeds verified the feasibility of the micro-contact temperature analysis. The results indicate that contact temperature between particles and workpieces linear increases as particle size and rotational speed increase. The particle density has a negligible effect on maximum contact temperature between particles and workpieces.

Influence of Contact Temperature on Contact Fatigue Failure Forms: Part 1—Contact Temperature Analysis of Rolling-Sliding Contact Specimen

Under rolling-sliding contact, specimens have different failure forms, such as pitting and spalling etc. The surface roughness of specimen in contact has a strong influence on the failure form. The elevated contact temperature produced by a rougher surface is one of the key factors in producing changes in failure form. According to the results of the test and the analysis, the following viewpoint is suggested to explain the influence of the roughness on failure forms: the rougher contact surface produces elevated contact temperature; the elevated contact temperature causes the material yield strength over local areas to reduce transiently thus resulting in a plastic deformation layer, and have the change of failure form. The present study includes two parts: in the first part, the analysis of contact temperature distribution is carried out; in the second part, the results of the test and analysis are discussed.