|
ZHAO Xin
JIN Xuesong
ZHAI Wanming
State Key Laboratory of Traction
Power,
Southwest Jiaotong University,
Chengdu 610031, China
|
|
|
ANALYSIS OF THERMAL-ELASTIC
STRESS OF WHEEL-RAIL IN
ROLLING-SLIDING CONTACT*
Abstract: A coupling thermo-mechanical
model of wheel/rail in rolling-sliding contact is put forward
using finite element method. The normal contact pressure is
idealized as the Hertzian distribution, and the tangential force
presented by Carter is used. In order to obtain thermal-elastic
stress, the thermal-elastic plane stress problem is transformed
to an elastic plane stress problem with equivalent fictitious
thermal body force and fictitious boundary distributed force.
The temperature rise and thermal-elastic stress of wheel and
rail in rolling-sliding are analyzed. The non-steady state heat
transfer between the contact surfaces of wheel and rail,
heat-convection and radiation between the wheel/rail and the
ambient are taken into consideration. The influences of the
wheel rolling speed and wear rate on friction temperature and
thermal-elastic stress are investigated. The results show the
following: ① For rolling-sliding case, the thermal stress in the
thin layer near the contact patch due to the friction
temperature rise is severe. The higher rolling speed leads to
the lower friction temperature rise and thermal stress in the
wheel; ② For sliding case, the friction temperature and thermal
stress of the wheel rise quickly in the initial sliding stage,
and then get into a steady state gradually. The expansion of the
contact patch, due to material wear, can affect the friction
temperature rise and the thermal stress during wear process. The
higher wear rate generates lower stress. The results can help
under-stand the influence of friction temperature and
thermal-elastic stress on wheel and rail damage.
Key words:
Wheel/rail friction Thermal stress
Temperature rise Heat transfer
Finite element method |