Longitudinal rail weld geometry control and assessment criteria

Weld defect formation in rail thermite welds

A previously developed heat transfer model is used to study the influence of welding parameters on weld defect development in thermite welds. Weld defect formation maps are constructed from a series of heat transfer simulations. For the current normal rail thermite welding conditions, it is found that shrinkage cavity formation can be avoided but cold-lap and centre-line defects are likely to o...

Neurofuzzy model-based predictive control of weld fusion zone geometry

A closed-loop system is developed to control the weld fusion which is specified by the topside and back-side bead widths of the weld pool. Because in many applications only a top-side sensor is allowed which is attached to and moves with the welding torch, an image processing algorithm and neurofuzzy model have been incorporated to measure and estimate the top-side and back-side bead widths bas...

Optimal Maintenance and Renewal Strategy Due to Rail Track Geometry

Relation between the geometry of rail welds and the dynamic wheel–rail response: numerical simulations for measured welds

The primary mechanisms playing a role in the dynamic wheel–rail response to rail weld irregularities in a ballasted track are pointed out. The concept of P1 and P2 forces for metallurgical rail welds, introduced in a first paper [1] concerning the present research, is further elaborated. The dynamic wheel–rail response is simulated for a number of geometrical rail weld measurements. Results sho...

Information Geometry and Maximum Likelihood Criteria