Common Concept Misunderstandings In Transportation Simulation Test Machine

Misunderstanding 1: "Is the 3:1 strengthening factor of the transport platform better than 1:1? Is the higher the better? A higher factor can equivalently increase the test intensity and shorten the test time?

The ratio of the strengthening coefficient of the transportation simulation test machine should be consistent with the test time. The general strengthening coefficient and test time of the transport simulation vibration testing machine are both 1:1. If you want to change the strengthening factor, you need to adjust the height of the bump and the motor speed of the test machine, and use a spectrum analyzer to test while adjusting, measure the machine’s acceleration RMS value, and then use the measured value to calculate the strengthening coefficient of the machine until it reaches the required value, record the state of the test bench at this time, record the position of the bump and the motor speed value, and set it according to the recorded data when you start the experiment next time. It is worth noting here that if the blind and one-sided pursuit of a high strengthening factor will increase the operating strength of the equipment, the use of the stress environment will be harsh, similar to the accelerated life test, and will reduce the service life of the test machine. Therefore, it is recommended that the strengthening factor and the test time are 1:1.

Misunderstanding 2: "The faster the drive motor rotates, the faster the car speed is? Changing the motor speed is equivalent to changing the car speed?"

Once the motor speed is determined, the motor speed cannot be easily changed after being measured and recorded by the authentication department. If it is changed at will, the acceleration RMS value and power spectrum function of the mechanical testing system will change greatly, exceeding the qualified range of the national standard, so that the test machine will not be qualified when it is measured again. Here I emphasize a misunderstanding, that changing the motor speed value can simulate the test of different vehicle speeds. This is a serious mistake. The motor speed value can only change the acceleration RMS value and power spectrum of the test, but not the speed of simulated vehicle.

Misunderstanding 3: "How to choose the road grade on the transportation simulation test machine? How to set the vehicle speed?"

The third and fourth levels of the road surface are determined by national standards according to different road conditions. Generally speaking, when doing vehicle transportation tests, national standards will stipulate how many kilometers should be driven at what speed on several levels of road. When a transportation simulation test machine is used for testing in a laboratory, just divide the total mileage specified by the standard by the vehicle speed to get the test time, and use this test time to do it on the shock and vibration test machine. Because of the different road grades, the required vehicle speed and total mileage are also different. As long as we do enough time for the calculated test, we can meet the national standards for different road grades and different vehicle speeds.

Misunderstanding 4: "After entering the vehicle speed and time on the control software interface, what does the equipment operating curve show?"

The only variable that can be set in the transportation simulation test machine is the test time. It is sufficient to have a test time setting window on the control cabinet panel, without using computer software for control. Some manufacturers recommend the use of computer software control to divide the settable variables into: highway level, vehicle speed, time, etc. This is a misunderstanding of the simulated transportation test and misleading users. It has no practical meaning; the only reference is the vibration energy (power spectrum) the test specimen bearing.