The Mechanics of Surface Modification for Rolling Element Performance

弹塑性滚动和滑动接触的有限元建模将扩展到近表面区域，以便它可以包括由于个别凹凸不平和表面不规则反复加载造成的表面损伤。这些不规则性在压力分布中产生强烈的峰值，并导致非常接近接触面的循环塑性和疲劳损伤。对于光滑接触表面，传统的赫兹理论无法解决这些影响，而成为由先进材料制成的滚动体失效的决定因素。不规则影响的建模将扩展到研究它们对具有浅改性表面层和涂层的物体的影响，以确定这些层的哪些特性和尺寸能使滚动元件性能最佳。

Finite element modeling of elasto-plastic rolling and sliding contact will be extended to the near-surface region so that it can include surface damage due to repeated loading of individual asperities and surface irregularities. These irregularities produce intense spikes in the pressure distribution and result in cyclic plasticity and fatigue damage very close to the contact surface. The effects are not addressed by conventional Hertzian theory for smooth contact surfaces and become determining factors in the failure of rolling elements made from advanced materials. The modeling of the effects of irregularities will be extended to also study their effects on bodies with shallow modified surface layers and coatings in order to determine which properties and dimensions of these layers give optimal rolling element performance.