Dynamic lubrication analysis of connecting rod is a very complex problem. Some factors have great effect on lubrication, such as clearance, oil viscosity, oil supplying hole, bearing elastic modulus, surface roughness, oil supplying pressure and engine speed and bearing width. In this paper, ten indexes are used as the input parameters to evaluate the bearing performances: minimum oil film thickness (MOFT), friction loss, the maximum oil film pressure (MOFP) and average of the oil leakages (OLK). Two orthogonal experiments are combined to identify the factors dominating the bearing behavior. The stepwise regression is used to establish the regression model without insignificant variables, and two most important variables are used as the input to carry out the surface response analysis for each model. At last, the support vector machine (SVM) is used to identify the asperity contact. Compared with SVM model, the particle swarm optimization-support vector machines (PSO–SVM) can predict the asperity contact more precise, especially to the samples near dividing line. In future work, more soft computing methods with statistical characteristic are used to the tribology analyses. the velocity in the circumferential direction of the bearing (U 1 =0) the velocity in the circumferential direction of the crankshaft the oil film thickness the oil film pressure the lubricant viscosity the coordinate axis along the horizontal direction the coordinate axis along the axial direction the pressure flow factors the pressure flow factors the shear flow factor the composite rms roughness filling factor represents the original radical clearance at the underformed state the crankshaft deformation in x direction the crankshaft deformation in the z direction radical deformation of the bearing measured from bearing crown the composite elastic modulus, E ′ = ( ( 1 − v 1 2 ) / E 1 + ( 1 − v 2 2 ) / E 2 ) − 1 the Poisson ratio and Young's modulus of the adjacent surfaces the asperity density the radius of curvature of convex peak the dimensionless clearance parameter, H = H/σ flow-rate from the front-end plane of the bearing flow-rate from rear end of the bearing total end leakage flow rate of lubricant asperity contact shear force fluid shear force 
Tribilogical performances of connecting rod and by using orthogonal experiment, regression method and response surface methodology