Thermal Effects and Mitigation Methods for Continuous Sheet Guideways

摘要

The report summarizes work completed in the assessment and analysis of thethermal effects and mitigation methods for continuous sheet Maglev guideway structures. The thermal problems are identified and assessed in a literature search and review of design codes. Advanced heat transfer and structural analyses and parametric studies are performed to quantify the severity of these effects. Guideway deflections are found to be large and possibly inadmissible (if not mitigated) for Electromagnetic Suspension (EMS) systems. The adverse impact of thermal deflection on passenger ride comfort is also assessed. Continuous Sheet Guideway (CSG) thermal buckling, fatigue and fracture are addressed. Additional guideway heating effects due to vehicle induced eddy currents are found to be very significant in adversely affecting buckling and inducing cyclic thermal stresses. Techniques for controlling these thermal effects in both the primary structure and CSG are discussed. Alternating continuous support conditions and white surface coatings are shown to help in reducing thermal deflection in the primary structure. The use of expansion gaps and some innovative attachment and mitigation techniques for CSG are also presented. Requirements for design data and test validation of the advanced analysis are identified, and considered critical for the development of successful design methodology of Maglev structures.