Design Optimization of a Car-Truck Stand

Abstract

Car-truck stands are used during maintenance operations to support one end of a freight car or a commuter car used in railway industry. Usually, they consists of several pieces of steel tubes and other steel members welded together to form a rigid frame structure. From a safety perspective, the car-truck stands are to be designed carefully, but at the same time due to their possible large volume of production, this structure needs to be optimized from strength and cost perspectives besides other parameters such as long life, etc. The purpose of this paper is to conduct virtual experiments for the optimal design of a different car-truck stand structures using Autodesk Simulation program as a CAE tool. The idea is to include this work as a part of final project in a traditional finite element analysis (FEA) course taught at Kettering University. For the work reported here, the structural steel members are simplified by using standard pipe sections, which are then optimized for strength and weight reduction, as well as for buckling. It is hoped that through this study a clear understanding of assumptions made in the FEA course topic on frames is realized by the students. Initial assessment done indicates that students appreciated the use of a CAE tool for optimal design of frames and other structural members.

Multi-Material Optimization of a Simplified Railcar Truck Stand

“…As expected, the top two members (labeled as Member 1 in the Table) experience the maximum deformation of nearly 1.2 mm, which is quite acceptable, being very small. The results of previous work using AutoDesk [8] gave exactly the same result of 1.19 mm. Both NX and AutoDesk 1D simulations yielded similar results since the solution process for 3D space frames and the database used for the steel pipe schedule are almost identical.…”

“…Figure 2 shows the sketch of the CAD model of the preliminary design of the newly proposed box frame using AutoDesk (left) [8] and NX (middle). The sketch on the right in Figure 2 shows the different circular sections used for the members isolated at the top joint (node) in the finite element analysis (FEA).…”

“…This is a good learning outcome for the students to realize that multiple design iterations are needed. Keeping in mind that one of the objectives of this paper is first to validate the results of the earlier published work [8], FEA has been performed using 1D mesh in NX.…”

“…This is somewhat consistent with how the load is applied to the vertical frame members of the original stand shown in Figure 1. Also, this model is similar to the earlier work [8]. Since the stand is intended to be used for different types of wagons and an engine, the typical weight of a freight train engine is used in the design.…”

“…However, this list by no means is complete. The work reported in this paper is based on an earlier work published in ASEE by the current author along with the other co-authors [8], and the work presented by one of the students at MS&T conference [9]. The senior elective course is offered as an independent study few times with enrollment each time of no more than 4 to 6.…”