弹簧应力松弛载荷的在线测量新方法

目的 准确高效地测量弹簧在应力松弛试验过程中的载荷。方法 针对周期试验法中繁琐的拆装工作和连续试验法中测试效率偏低的难点问题，以周期试验法中可以让“弹簧的总形变量在短时间内发生变化”的事实为依据，通过驱使待测弹簧进一步发生少量变形，将待测弹簧承受的准不变载荷转换为缓冲弹簧的连续变化载荷进行测量。测量后分别对直线进行拟合，便可求得驱动力F0，进而可以计算出待测弹簧处于装夹状态时所承受的载荷。结果 得到了一种在应力松弛过程中测量弹簧载荷的新方法，并结合螺旋压缩弹簧的结构特点，介绍了该方法的2种实现方式。当置信度为0.95时，测试结果的置信区间在±2%内，说明测量结果具有较高的可信度。结论 实践应用表明，在周期试验法中，采用该方法能够避免繁琐的拆装过程，有利于降低人为误差；在连续试验法中，采用该方法可以提高测试效率，从而有效地解决应力松弛试验中的载荷测试难题。

New Method for On-line Measurement of Spring Load during Stress Relaxation

The work aims to accurately and efficiently measure the spring load during the stress relaxation. In view of the tedious disassembly work in periodic test method and the low efficiency in continuous test method, and based on the fact that the "total shape variable of the spring can be changed in a short time" in the periodic test method, the spring to be measured was driven to further have a small amount of deformation, so the quasi invariant load of the spring to be measured was converted into the continuous variable load of the buffer spring for measurement. After the measurement, the driving force F0 could be obtained by fitting the straight lines, and then the load of the spring to be measured in the clamping state could be calculated. A new method of measuring spring load in stress relaxation was proposed. Then, the two implementation methods of this new method were introduced in combination with the structural characteristics of spiral compression spring. When the confidence was 0.95, the confidence interval of the test results was within ±2%, indicating that the measurement results had high reliability. It is shown that the new method can avoid the tedious disassembly process and reduce the human error in the periodic test method, and improve the test efficiency in the continuous test method, thus effectively solving the load test problem during the stress relaxation.