The Simulation of One Metro Wheel Tread Temperature in Cycle Braking Condition

Abstract

Abstract. To simulate the tread temperature rise of the working subway train in the process of its normal operation and to explore the temperature rise limit of wheel tread during operation, finite element numerical simulation was used in this paper. Based on heat transfer theory and finite element method, a three-dimensional finite element model of the subway wheel was created. According to the braking condition of main line pure air brake, thermal simulation of wheel temperature field was conducted and finally the temp-rising law of the metro wheel was achieved. The results show that the wheel tread temperature first increased rapidly and then slowly decreased until the next brake in a period of "brake, stop, accelerate and coast", with the temperature raised about 110°C in a single brake. At first, the braking heat accumulated in the wheel, with the overall temperature gradually increasing. Then, after several consecutive braking processes, the overall temperature tended to be stable. The tread temperature reached its peak at 3766.5s, with the highest temp reaching 298.9°C during the 31st braking process, not exceeding the limit of temperature rise (400°C ).

Modeling of braking thermal effect for wheel-rail contact parameters

“…According to Hertz theory, the contact area between two non-conforming surfaces is elliptical and the dimensions of the contact patch are given by equation (1) where, a and b are the semi-major and semi-minor axes of the contact ellipse. The values of a and b depend on the applied normal load, F, Young's modulus, E and Poisson's ratio, of the material and radii of profiles of wheel and rail.…”

“…The wheel will be subjected to cyclic fluctuations in temperature as it loses heat to surrounding air by convection after leaving contact with the brake shoe or the rail, resulting in thermal fatigue which may eventually develop cracks due to expansion of the outer surface of the rim producing compressive stresses in the interior region. [1][2][3][4][5] The equations developed by Fischer and Wiest 6 using elliptic integrals were simplified by Tanaka 7 with ordinary integrals to obtain the expressions for major and minor axes of the contact patch and contact pressure. Using the equations of Tanaka, 7 Satryo et al 8 have studied the influence of increasing wheel and rail profile radii and decreasing the taper on contact parameters and compared their results with those obtained by the solutions of Fischer, FEA and Hertz theory.…”

The Parameter Identification of Physical-Based Constitutive Model by Inverse Analysis Method for Application in Near-Net Shape Forging of Aluminum Wheels

“…Yang et al [3] conducted finite element analysis on the forging process of 6061 aluminum alloy wheels based on the obtained friction coefficient, determining the maximum forming load, temperature, and equivalent stress distribution of the wheel forging process. In these studies [1,[4][5][6][7], a rolling or spinning process was required for the wheels to form rims with a thin and complex radial cross-section after the forging process was finished. In Kim et al's [1] study, wheels were formed by forward and backward extrusion, followed by machining and rolling steps to obtain the complete product shape.…”

“…In Kim et al's [1] study, wheels were formed by forward and backward extrusion, followed by machining and rolling steps to obtain the complete product shape. Ma et al [4] and Zhang et al [5] proposed a process for forged aluminum alloy wheels, and the process steps included rotary forging, initial forging, final forging, flaring and spinning for rims, etc. Chen et al [6] and Lu et al [7] investigated the effects of the process parameters on the forming quality and forming force during the forging and spinning processes of aluminum wheels.…”