RISK ANALYSIS BASED CWR TRACK BUCKLING SAFETY EVALUATIONS.
As part of the Federal Railroad Administration’s (FRA) track systems research program, the US DOT’ Volpe Center is conducting analytic and experimental investigations to evaluate track lateral strength and stability limits for improved safety and performance. This paper deals with a part of this research addressing the development of a comprehensive CWR buckling safety analysis which includes a risk analysis based approach for prediction of probable number of buckles on a given track. These risk based buckling evaluations are particularly useful for dealing with statistical variability in the track parameters. The risk approach can provide economic options for track maintenance to achieve the desirable buckling strength. The buckling risk methodology and the statistical parametric descriptors are discussed and a buckling risk analysis model is presented with illustrative examples. The model also provides a computational scheme for the determination of buckling probability as a function of maximum rail temperature when the key influencing parameters of track lateral resistance, lateral alignment defect and rail neutral temperature are given as statistical variables. The risk based approach as well as the previously developed deterministic approaches in CWR-BUCKLE and CWR-INDY are all being integrated in a single new computer program called CWR-SAFE. CWR-SAFE is a Windows based software analysis package for a comprehensive buckling safety evaluation for use by both the railroad industry and the research community.
PARAMETRIC ANALYSIS AND SAFETY CONCEPTS OF CWR TRACK BUCKLING
The report presents a comprehensive study of continuous welded rail (CWR) track buckling strength as influenced by the range of all key parameters such as the lateral, torsional and longitudinal resistance, vehicle loads, etc. The parametric study presented here is based on the computer program jointly developed by Volpe National Transportation Systems Center (VNTSC) and Foster-Miller. The computer program is based on the dynamic buckling theory developed and validated by previous research efforts of VNTSC. On the basis of test data, the practical range of each of the parameters involved has been identified and computer runs have been made over this range to yield the buckling strength variations and the sensitivity with respect to the parameters. Critical parameters and their ranges have been evaluated through this process. Several conclusions of practical interest are drawn from the study.
Britain and the Problem of International Disarmament: 1919-1934
Acknowledgements 1. Introduction 2. The Concept and Context of Disarmament, 1919-1934 3. The Human Element 4. The Lloyd George Coalition Government, 1918-1922 5. The Conservative Governments, 1922-1923, and the First Labour Government, 1924 6. The Conservative Government, 1924-1929 7. The Labour Government, 1929-1931 8. The National Government, 1931-1934 9. Conclusion Bibliography