Abstract:

In this paper,the dynamic stress characteristics of a working device of hydraulic excavator in a normaldigging process are investigated via dynamic test and transient analysis. Firstly,for a normal digging process ofbackhoe hydraulic excavator,synchronous test platforms were constructed respectively for the tests of dynamicstrain,oil pressure and angular displacement.Then,based on the d'Alembert principle,dynamic balance equa-tions of the boom,the arm and the bucket were respectively established and were used to calculate the dynamic loadspectrum of each hinge point with the test data.Moreover,the calculated dynamic load was transformed into the lo-cal coordinate system from the base one,which helps to perform a transient analysis later.Finally,the test resultsof dynamic stress were compared with those obtained by transient analysis.It is found that the stress obtained by thetwo methods are of the same variation law,and that the transient analysis helps to reveal the overall dynamic stresscharacteristics of the working device and provides a basis for the determination of dynamic stress distribution ruleand dangerous section of the working device.

Key words: excavator, structural strength, dynamic test, transient analysis, test platform, dynamic stress