中文摘要：

为改善心轨受力状态、提高固定辙叉直向通过速度,在分析固定辙叉伤损规律的基础上,提出基于车轮踏面所需高差值与辙叉轨顶廓型实际高差值之比（轮轨廓型净差值比）的固定辙叉优化设计方法.以既有60 kg＆#183;m-1钢轨18号整铸固定辙叉廓型与LM磨耗型车轮踏面的匹配为例,运用该方法对既有固定辙叉结构进行优化.研究表明：既有固定辙叉心轨的薄弱断面先于翼轨与车轮接触,导致心轨伤损严重;优化固定辙叉的R15 mm圆弧＋R80 mm圆弧＋1∶13斜线复合廓型能够明显改善心轨的承载状况,降低固定辙叉竖向结构不平顺及动轮载的幅值（分别降低45.3％和46.79％）,可作为与LM磨耗型车轮踏面匹配的固定辙叉廓型;基于轮轨廓型净差值比的优化方法能够针对任意型式车轮踏面进行相应固定辙叉的廓型设计.

英文摘要：

To improve the stress state of nose rail and the direct passing speed through rigid frog,and according to analyzing the failure rules of rigid frog,the optimization design method for rigid frog was proposed based on the height difference needed for wheel tread as well as the actual height difference ratio of rail top and frog profile （the net difference ratio of wheel/rail profile type）.Taking the matching between LM worn type wheel tread and 60 kg · m-1 rail No.18 integral cast rigid frog as an example,the existing rigid frog structure was optimized by the proposed method.The results showed that the nose rail of the existing rigid frog profile contacted with the wheel before wing rail,which led to the serious damage of nose rail.Optimizing the rigid frog profile composed of R15 mm arc,R80 mm arc and 1 ∶ 13 oblique line could significantly improve the loading status of nose rail and reduce the vertical structural irregularity of rigid frog and the amplitude of dynamic wheel load （reduced by 45.3％ and 46.79％ respectively）,which could be used as the rigid frog profile matching with LM worn type wheel tread.The optimization method based on the net difference ratio of wheel/rail profile is applicable to the design of the corresponding rigid frog profile for any kind of wheel tread.