The age of faster, longer, safer, quieter and more environmentally friendly trains is here. Safety is the paramount objective of any train design and cannot be compromised at any cost. Physical testing formed an integral part of design in the 1990s, until CAE demonstrated that many complex and unsafe tests could be simulated on a desktop. The NISA product line has helped the railway industry for the last two decades in analyzing many such tests and problems.
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Structural analysis of a locomotive canopy made of composite material
Composites are finding increased use in new age locomotives, because they are so lightweight and make more aerodynamic shapes possible. Structural analysis of a locomotive canopy was to be carried out to determine the static response of the composite structure under mechanical and aerodynamic loads.
The canopy of the engine was made of composite shell structure stiffened with orthogonal ribs on the interior surface. The entire unit was assembled from three sub-assemblies. The windshield of the canopy was made from laminations of bulletproof glass while rest is made of glass fiber reinforced plastic (GFRP). The canopy was fixed to the base frame of the locomotive by means of fasteners. The pressure field obtained from the CFD analysis was transferred to the structure to determine the static structural response. The stresses developed in the canopy skin and the ribs for the initial design at the front of the canopy were observed to be above the allowable limit. The skin thickness of the canopy including the bottom flange was therefore increased. The manufacturer saved on expensive physical trials.
Flow analysis of railway break resistor
The railways complained about the failure of a few electric locomotive brake resistors during certain braking conditions. Computational fluid dynamic analysis determined that inefficient cooling at the brake tips was the cause. A design change was incorporated which prolonged the life of the resistors considerably.
Cooling analysis of a heat sink
The above-shown heat sink allows the fast dissipation of heat from various electrical parts under a railway bogie. The fins of the heat sink point downwards and allow for air to pass through them when the train is in motion. A major railway parts manufacturer wanted to increase the efficiency of its heat sinks. Computational fluid dynamics and thermal analysis were conducted and a wavy-fin profile was suggested to increase efficiency.