During the use of the brake beam static load test loading device, strict control is required from four aspects: equipment debugging, loading operation, safety protection, and data recording. The following are specific precautions:
1、 Equipment debugging and inspection
Loading device calibration
Before the experiment, the loading device (such as hydraulic system, sensor) needs to be calibrated to ensure that the accuracy of the loading force value meets the test requirements (usually with an error of ≤ 5%).
Check if the connection between the loading device and the brake beam is secure to avoid looseness or displacement during the loading process.
Confirmation of brake beam status
Check the appearance of the brake beam to confirm that there are no defects such as cracks or deformations, especially in key parts such as the end shaft and roller shaft.
Preloading the brake beam (usually 10% -20% of the maximum test load) to eliminate inelastic deformation and ensure the accuracy of test data.
Verification of measurement point layout
Confirm that the installation positions of strain gauges, displacement sensors, and other measuring points meet the requirements of the test plan to avoid data distortion caused by improper arrangement of measuring points.
Check if the connection between the measuring point and the data acquisition system is stable to prevent signal interference.
2、 Loading operation specifications
Hierarchical loading control
Loading should be carried out in stages, with each stage typically loading 20% -25% of the maximum test load, gradually increasing to the design load.
After each level of loading, the load should be kept stable (usually lasting 5-10 minutes), and the next level of loading should be carried out after the data is stable.
Loading speed control
The loading speed should be slow and uniform to avoid rapid loading that may cause dynamic response of the brake beam and affect the results of the static load test.
For hydraulic loading systems, it is necessary to control the rate of increase in oil pump pressure to prevent sudden pressure changes.
Uninstalling program execution
Unloading should be carried out in stages, with each stage typically unloading 50% -100% of the loading amount, gradually releasing the load.
After unloading, it is necessary to observe the residual deformation of the brake beam and record the residual stress data.
3、 Safety protection measures
Test site safety
Warning lines and signs should be set up in the experimental area to prohibit unrelated personnel from entering.
Operators are required to wear personal protective equipment such as safety helmets and protective gloves to prevent falling objects from heights or accidental activation of equipment.
Equipment safety inspection
Regularly inspect the hydraulic and electrical systems of the loading device to ensure there are no safety hazards such as oil leakage or short circuits.
Perform stability checks on the support device of the brake beam (such as the reaction frame) to prevent overturning during loading.
Emergency plan preparation
Develop emergency response plans for abnormal test situations, such as loading device failures, brake beam fractures, etc., and clarify emergency response procedures.
The test site should be equipped with emergency supplies such as fire extinguishers and first aid kits.
4、 Data recording and analysis
Real time data monitoring
Real time recording of loading force, displacement, strain and other parameters using a data acquisition system to ensure data continuity.
Focus on monitoring key measuring points (such as end axis stress and beam deflection), and immediately stop loading if abnormal data is found.
Data verification and processing
After the experiment is completed, the collected data is verified to eliminate outliers and ensure data reliability.
Use professional software such as Midas and Bridge Doctor to process the data and generate analysis charts such as stress-strain curves and deflection curves.
Basis for judgment of results
Calculate the verification coefficient of the brake beam based on experimental data (the ratio of measured value to theoretical value), and determine whether its bearing capacity meets the standard.
Evaluate indicators such as residual deformation and crack development to determine whether the brake beam meets design requirements.