External load equivalent and load spectrum compilation ofloader based on moment equivalent(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2019年02期
- Page:
- 117-126
- Research Field:
- 汽车与机械工程
- Publishing date:
Info
- Title:
- External load equivalent and load spectrum compilation ofloader based on moment equivalent
- Author(s):
- WAN Yipin; SONG Xuding; LU Pengmin; YUAN Zhengwen
- 1. Key Laboratory of Road Construction Technology and Equipment, Ministry of Education, Changan University,Xian 710064, Shaanxi, China; 2. Engineering Machinery Research Institute, Xuzhou ConstructionMachinery Group, Xuzhou 221004, Jiangsu, China)
- Keywords:
- mechanical engineering; loader; moment equivalent; external load; load spectrum
- PACS:
- -
- DOI:
- -
- Abstract:
- To study the fatigue performance of the load spectrum of loader working device, an equivalent method of loader external load based on the bending moment section was suggested. When the loader loads the material, the load on the working device was simplified as a concentrated external load acting on the bucket and compiled the load spectrum. A boom coordinate system was constructed based on a hinge line at the front and rear ends of the moving arm, and the actual load of the bucket hinge point was transformed into a hinge load on the boom structure under the boom coordinate system. The synchronous relationship between the moment of the boom section and the external load of the working device was studied, and the action point position and direction of the external force was determined. The external load equivalent model of the working device based on the bending moment of the maximum bending moment section of the boom was established. Considering the load equivalent load of the bucket hinge point under typical working condition of the ZL50G loader working device as the basis, the statistical characteristics of mean load, frequency, and amplitude were obtained by rain flow counting. The load spectrum of the fatigue test program under various working conditions was determined. The results show that the position and direction of the equivalent external load on the working device can be accurately obtained based on the bending moment section equivalent method. The time history of the equivalent load is obtained by the bending moment section of the maximum bending moment section of the boom, and the value and change rule of the boom bending moment section are coincident under the conditions of equivalent load and measured load. The mean of the equivalent load is fit to the normal distribution and the amplitude is fit to the threeparameter Weibull distribution. The variable mean load spectrum for the fatigue test of the working equipment of the loader is compiled using rain flow counting and parameter extrapolation, and the loading time of the fatigue bench test is minimized. The proposed equivalent load model based on the bending moment section equivalent and the proposed method of compiling the load spectrum of the loader working device provide basis for the accurate evaluation of structural reliability and establishment of scientific indoor bench test specifications. 7 tabs, 9 figs, 19 refs.
Last Update: 2019-04-01