Improved Tank Car Design Development: Ongoing Studies on Sandwich Structures

Abstract

The Government and industry have a common interest in improving the safety performance of railroad tank cars carrying hazardous materials. Research is ongoing to develop strategies to maintain the structural integrity of railroad tank cars carrying hazardous materials (hazmat) during collisions.This paper describes engineering studies on improved tank car concepts. The process used to formulate these concepts is based on a traditional mechanical engineering design approach. This approach includes initially defining the desired performance, developing strategies that are effective in meeting this performance, and developing the tactics for implementing the strategies. The tactics are embodied in the concept. The tactics and concept evolve through engineering design studies, until a design satisfying all of the design requirements is developed.Design requirements include service, manufacturing, maintenance, repair, and inspection requirements, as well as crashworthiness performance requirements.One of the concepts under development encases the pressurized commodity-carrying tank in a separate carbody. Moreover, this improved tank car concept treats the pressurized commodity-carrying tank as a protected entity. Welded steel sandwich structures are examined as a means to offer protection of the commodity tank against penetrations from impacting objects in the event of a collision. Sandwich structures can provide greater strength than solid plates of equal weight. Protection of the tank is realized through blunting of the impacting object and absorption of the collision energy. Blunting distributes impact loads over a larger area of the tank. Energy absorption reduces the demands on the commodity tank in the event of an impact. In addition, the exterior carbody structure made from sandwich panels is designed to take all of the in-service loads, removing the commodity tank from the load path during normal operations.Design studies described in this paper focus on the protection aspect of using sandwich structures. Studies are conducted to investigate the influence of different parameters, such as sandwich height and core geometry, on the forcedeformation behavior of sandwich structures. Calculations are carried out numerically using nonlinear finite element analysis. These analyses are used to examine the crashworthiness performance of the conceptual design under generalized impact scenarios.

Detecting the effect of an intermediate adapter on the load of the bearing structure of an open wagon

“…The advantage of this study in comparison with [4,5,[7][8][9]] is that we proposed solutions aimed at reducing the vertical load of the supporting structure of the car, as for the most common type of oscillations in operation. In contrast to work [6], in order to ensure the strength of the supporting structure of the car, we proposed not to strengthen it but to reduce the dynamic load. In comparison with works [10,11], the proposed solution to reduce the dynamic load of the supporting structure of the car can be implemented without its improvement.…”

“…In order to improve the strength indicators of a railroad car, the creation of its components in the form of multilayer elements is proposed in [6]. The article provides an implementation option for this advancement.…”

“…Our review of the literature [4][5][6][7][8][9][10][11] shows that improving the load-bearing structures of vehicles to reduce their load in operation is relevant. However, it is important to say that due attention has not yet been paid to measures to reduce the vertical load of cars under the action of cyclic loads.…”

Generalized railway tank car safety design optimization for hazardous materials transport: Addressing the trade-off between transportation efficiency and safety

“…This work is intended to identify designs with considerably better safety performance to weight ratios than are possible using conventional steel tank car designs. In addition to consideration of new and stronger steels, this research is also developing and evaluating new composite materials and corrugated metal structures that are intended to absorb the energy of an object impacting a tank car before it penetrates the tank itself [11][12][13][14]. New valve designs are also being evaluated that will substantially reduce the likelihood of release in an accident [15].…”

Investigation of the influence of an intermediate adapter on the dynamic load of a supporting structure of a platform wagon

“…The analysis of the latest studies devoted to the issue of improving freight wagon designs in order to reduce the impact of dynamic loads on the load-bearing structure allow to conclude their relevance [3][4][5][6][7].…”