摘要
列车速度的提高和车辆轴重的增加导致轮轨接触应力加大,引起车轮轮辋内部应力分布的变化。根据铸钢车轮轮辋金相分析结果,应用Goodier方程对轮辋处夹杂物和空穴周围的应力状态进行分析。在轮轨接触应力作用下,Al2O3球形夹杂物在其球体的"极点"位置产生应力集中,而空穴处于"赤道"位置,其应力更大。根据Murakami公式,以轴重为25 t的车轮为例,计算在不同运行速度下,距铸钢车轮踏面一定深度的夹杂物临界尺寸。其结果显示,在一定车速下,夹杂物的临界直径随距踏面深度的增加而增大;若深度一定,夹杂物的临界直径则随车速的提高而变小。当轮辋中夹杂物的尺寸大于该临界直径时,轮辋疲劳裂纹就可能萌生。
The increase of speed and axle load will lead to the increase of wheel-rail contact stresses,which will make a great change of stress distribution in the whole wheel rim.According to metallographic analysis results of the wheel-rim of the cast-steel wheel,the Goodier equation was employed to analyze the stress state around inclusion and cavity.As regards the distribution of wheel-rail contact stresses,stress concentration occurred at the points of up and down of Al2O3 spherical inclusion,while it appeared on the horizon plane of cavity.The critical inclusion sizes of the 25 t axle-load-freight-car wheel at different velocities,a certain distance away from the tread,were calculated by the Murakami equation.The calculation results show that when the velocity is constant,the critical inclusion size increases with the increasing of the depth away from the tread;when the depth away from the tread is constant,the critical inclusion size decreases with the increasing of the running velocity.Wheel-rim fatigue cracking may be initiated once the inclusion size is bigger than the critical inclusion size.
出处
《铁道学报》
EI
CSCD
北大核心
2010年第4期108-113,共6页
Journal of the China Railway Society
基金
国家高技术研究发展计划(863计划)(2006AA03Z514)
关键词
重载
接触应力
夹杂物临界尺寸
轮辋疲劳裂纹
heavy-haul
contact stress
critical inclusion size
wheel-rim fatigue cracking
