HLA Engineers, Inc., has worked on railcar design and analysis since the beginnings of the company in 1974. H. Keith Hunt, HLA President, performed the first finite element analysis of a railcar in 1972 for Trinity Industries, Inc. when he analyzed and assisted in the redesign of the Trinity Industries' 5800 cu.ft. plastic pellet car. Since that time, HLA Engineers has designed or participated in the design and analysis of literally all types of railcars. Numerous AAR Stress Analyses have been performed on the same cars listed above - both finite element stress analyses and classical analyses for AAR approval. HLA is acquainted with key personnel at both the AAR and DOT, and is familiar with the governing codes.

HLA has actively designed railcars both from conception and modification since 1974:

• Open top and cover hopper cars (both stub and thru sill)
• High side gondolas
• Pulp wood cars
• Flats
• Tank Cars

HLA has analyzed and performed stress analysis on virtually every type of car, including:

• Open top and covered hopper cars  (both stub and through sill)
• Gondolas
• High side gondolas
• Box Cars
• Flats, Bulkhead Flats
• Pulp Wood
• Plastic Pellet
• Pressure Differential
• Tank and Cryogenic Tank Cars
• Inter-modal articulated well, stand-alone well, and spine cars.

Damage Tolerance Analysis

An on-going project at HLA is the fatigue and Damage Tolerance Analysis of various tank car designs. HLA has finalized the mesh refinement of the head brace area of one client's Stub Sill Tank Car, for the purpose of a fracture mechanics crack growth study. This study is intended to predict the damage tolerance of the Client's car design in the head brace area, and mathematically establish an inspection frequency for the car so that cracks may be visually detected and repaired well in advance of reaching their critical length.

The computer model under refinement is one of four ultra-fine mesh models developed for various clients recently at HLA, for this same purpose. Special purpose computer software has been written by HLA Engineers to aid in coding the models, which are literally "state of the art" in refinement, and contain well over 100,000 degrees of freedom for a quarter-car model alone. The program NASGRO has also been acquired, and techniques developed to apply it to the analysis of crack growth using the results of the finite element model.

Cryogenic Tender Car

A recent HLA railcar project was the design of an LNG Tender Car. This car is to be used as a new fuel source for locomotive fuel. This car is to be used as a "fuel tank" carrying liquid natural gas: a new source for locomotive fuel. This car is a double-wall, evacuated and pearlite-insulated tank. HLA is generating all design drawings for the car outer shell and running gear. The customer is generating the cryogenic vessel design, although HLA has also designed many cryogenic storage vessels to ASME Section VIII, Division 2 rules.

 Nuclear Waste Car

One rail car project, for Stoller Corporation, Boulder Colorado, involved the finite element computer analysis of an existing open-top rail car to be used for the transportation of nuclear waste (low level radiation) for the Rocky Flat Arsenal. These cars were operated by the Department of Energy, but needed approval by the Department of Transportation for the specific rail travel. Several accident scenarios were devised by the DOT to prove the structural integrity of, and to certify the cars:

1.     Impact into a bridge abutment at 45 mph.

2.     Glancing impact into a wall, then rolling down an embankment.

A detailed computer model was made by HLA of the existing car. The finite element analysis of the model included transient-dynamic impact analysis, material plasticity and large displacement non-linearities. HLA participated in the redesign effort on the car, reinforcing the car for energy absorption and impact stresses.

Summary

HLA has been at the forefront of rail car analysis and design, through the use of state of the art computer and classical techniques. In doing so, HLA maintains a unique "feel" for the car structures, and an understanding of the for the industry as a whole.

HLA has also performed design and analysis of ASME pressure vessels (Section VIII, Divisions 1 and 2), cryogenic pressure vessels, ISO intermodal tank and dry cargo containers, MC 331 transports and many other types of transportation equipment.

©2007 HLA. All Rights Reserved  Privacy Policy | Legal Statement | Home | About Us
 Specialties | Projects | Contact Us | Job Opportunities | Management | Site Map