Excavator's boom fatigue test program spectrum managing and test loading method

Abstract

The invention discloses an excavator's boom fatigue test program spectrum managing and test loading method. The method comprises the concrete processes of 1, preparing basic data for compiling a load spectrum; 2, determining an excavator's boom fatigue test loading scheme; 3, taking the maximum bending moment of the boom as the load equivalent basis, and calculating the equivalent vertical load; 4, compiling the equivalent vertical force-time history into a boom calculation load spectrum; and 5, adopting the damage consistence principle at the fatigue key part stress measuring point to correct the calculation load spectrum, and finally obtaining the boom fatigue test program spectrum. The method is based on the actually-measured load, simplifies the fatigue test and represents the actual stress state of the boom to the greatest extent.

Description

technical field [0001] The invention relates to the technical field of engineering machinery, in particular to an excavator fatigue test program spectrum sorting and test loading method. Background technique [0002] Fatigue test is a powerful means of fatigue research. Fatigue test should simulate the real situation as much as possible. Load spectrum is the basic data for fatigue test. Therefore, load spectrum must be sorted out accurately and effectively. Fatigue tests are divided into constant-amplitude loading, program loading and random loading according to different loading methods, and the load spectrum is also divided into constant-amplitude loading spectrum, program loading spectrum and random loading spectrum. Constant amplitude loading can simplify the test, but it is not as good as program loading in reflecting the influence of load sequence and its change history; random loading can take into account the load sequence and can reflect the influence of real load o...

AI Technical Summary

Problems solved by technology

[0003] For components or complete machines with constant working posture and fixed load direction, the fatigue test posture is easy to determine, and the measured external load can be directly used to sort out the load spectrum, and can better reproduce the actual service situation, for example, engineering vehicle transmission system, etc.; while the excavator working device has multiple degrees of freedom, the actual working attitude and the size and direction of the external load are changing all the time, it is difficult to directly use the measured load to sort out the load spectrum of the whole machine that can reflect the actual situation

[0004] The literature "R961 Hydraulic Excavator Arm Load Spectrum" and the literature "Study on the Loading Spectrum of Single Bucket Hydraulic Excavator Model Simulation Test" adopt simplified forms, both of which are fatigue tests of the excavator working device in a fixed posture. The former uses the stress at the dangerous point of the stick as the equivalent of the tip loading force, and the test can only ensure that the stress state at the dangerous measuring point on the stick is the same as the actual one; the latter uses the stress at the dangerous point of the boom as the equivalent of the tip loading force, which can only guarantee the same For the stress of a dangerous measuring point on the boom, the two methods cannot determine whether the stress of other parts is consistent with the actual state, and the stress state of the dangerous point is closely related to the detailed structure. Applicable to excavators of the same model as the test prototype

[0005] There are still relatively few researches on the fatigue test of excavator boom components in the existing literature. The main difficulty is that the actual external force on the boom during the working process of the excavator is complex, and it is difficult to sort out the load spectrum for fatigue tests that can reflect the actual force state of the boom.

Images