Analysis on the Dynamics Performance of the Freight Car Negotiating the Small Radius Curve at Low Speed

Based on the data of the dynamics performance test with respect to speeded freight cars and regular freight cars with 8A bogie at low speed passing through small radius curve and 12# turnout side line,the dynamic performances of these cars through small radius curve and turnout side line were analyzed.The result shows that in the normal technology state when speeded freight cars with K2,K4,K5,K6 bogie and regular freight cars with 8A bogie at low speed passing through small radius curve and turnout side line,their dynamic performances basically meet the requirement of the standard.Thus,it is safe for freight cars passing small radius curve.With regard to speeded freight cars,when passing small radius curve,the unfavorable influence for vehicle safety is increased because of the outer rail cant reduction and deloading wheels of outer lateral.Therefore,velocity of speeded freight cars must be strictly controlled within the permitted velocity range of line regulation.By analyzing the characteristic of wheel and rail stress change for each wheel when the freight cars passing the small radius curve,the wheel-rail stress change of the empty speeded freight cars is more moderate than that of loaded cars,which is favorable to the safety of freight cars passing the curve.When regular freight cars passing the curve,the load of cars approximately in average is applied to left and right side frame by center plate.Then,the wheel-rail stress change is not distinct and the vertical force is not obviously changed.