Cracking was discovered in the headstocks of railway vehicles. The headstocks are critical components that support the weight of the vehicle and transfer loads from the bogies to the body. The client needed to assess the remaining fatigue life of the headstocks and determine if they needed to be replaced or repaired.
Strain Gauge Survey for Fatigue Analysis of Rail Headstock Case Study
HRL helps identify potential safety issues in rail headstock
Challenge
Solution
HRL proposed a strain gauge survey to obtain actual stresses occurring in the headstock under various operating conditions. Strain gauges are sensors that measure changes in length or deformation of an object when subjected to external forces. By installing strain gauges at strategic locations on the headstock, HRL could measure the strains caused by different loads and movements during operation.
The installation of strain gauges and testing was performed by HRL. The testing involved running the rail vehicles under different operating conditions while recording data from the strain gauges. The data was then processed and analysed using specialised software to determine stress ranges and fatigue damage.
Results
The strain gauge survey provided valuable data that allowed an engineering consultancy firm to perform a fatigue assessment using rain flow results provided from testing data. Rain flow analysis is a method used to extract stress cycles from time histories of stresses or strains. The stress ranges were found to be at a level that could cause metal fatigue, which confirmed the initial concerns about cracking in the headstocks.
Based on this analysis, it was recommended that all affected headstocks be replaced or repaired as soon as possible to avoid any potential safety issues. The client followed this recommendation and replaced all affected headstocks, ensuring the safety and reliability of their vehicles. This highlights how a strain gauge survey can provide valuable data for fatigue analysis and help identify potential safety issues before they become critical problems. By working with the experienced professionals at HRL, our clients are assisted in ensuring that their systems are safe, reliable, and meet all necessary regulatory requirements.
