Finite Element Analysis Improves Design of Hot Metal Ladle Car

Abstract

Abstract An electric powered Hot Metal Ladle Car was designed to safely transport a ladle filled with 160 metric tons of molten steel. The ladle geometry and space constraints within the use environment were specified. A final design was prepared and documented which met the design requirements and could be efficiently manufactured. An initial design was developed using past designs of a similar nature as a basis. By hand stress calculations were performed and the design modified to get stress values to acceptable levels. Preliminary design drawings were developed. At this stage of the design, some engineering personnel felt that the “by hand” stress analysis was sufBciently accurate to go ahead with fabrication. After much discussion it was decided to perform a Finite Element Analysis (FEA) to verify the design stresses calculated “by hand”. The FEA analysis predicted stresses that were significantly higher than indicated “by hand” in some critical change of section regions. These stress levels were much higher than the allowable stresses for this design. The difference between the FEA stresses and “by hand” stresses were evaluated. After much discussion and thought an insight to the actual load flow was developed which was consistent with the FEA results. With this insight, modifications were made to the design and incorporated into the FEA model. These changes needed to be practical from a manufacturing and end use viewpoint. After a few iterations on the design tire FEA stresses were reduced to an acceptable level. These changes were incorporated into the design. The final design of the ladle car was fabricated. The design was significantly improved due to the ability to accurately calculate stresses in transition regions of the frame where “by hand” methods were not really applicable. The combination of “by hand” methods to ballpark a design and FEA methods to reftne a design proved to be a powerful method to get a truly good design.