Additional bending normal stress measurement bridge circuit in bending combination test apparatus

Abstract

The invention relates to an additional bending positive stress measuring bridge circuit in the bending twisting composite testing device, which consists of a aluminium alloy cylinder cantilever and a crank perpendicular to the cantilever; four 45 degrees -3 right-angle strain rosettes are disposed on the circumference of the aluminium alloy cylinder cantilever in the sequence of strain rosettes A, strain rosettes B, strain rosettes C and strain rosettes D with right angel interval there between. The invention is characterized in that: on the axis direction of the cylinder cantilever, the strain rosettes B, strain rosettes C and strain rosettes D toward a same direction, while the strain rosettes A towards the opposite direction of the three, and the measurement point on the circumference is symmetry center. the invention can achieve higher measure precision in moment and torque, and can measure shearing force effectively, thereby can add new teaching experiment content, and can provide reference to internal force measurement of similar member in the engineering structure.

Description

[0001] This application is a divisional application with the application number "200610088185.1", the filing date of "June 30, 2006", and the title of the invention "Bending-Torsion Combined Test Device and Its Application in Internal Force Measurement". technical field [0002] The invention relates to a bending combined test device. Background technique [0003] Resistance strain measurement technology is one of the main methods for stress analysis of engineering structure tests, and is widely used in various engineering and technical fields such as machinery, civil engineering, and aerospace. Learning the principle of resistance strain measurement, mastering its measurement methods and techniques, and being able to apply them proficiently is a basic experimental skill that students in engineering colleges, especially those majoring in engineering technology, must master. Therefore, the electrical stress test is one of the essential and important contents in the experiment...

AI Technical Summary

Problems solved by technology

When measuring with a 45°-3 right-angle strain rosette, since the center of the sensitive grid does not coincide with the measuring point, when the full bridge is used to measure the bending shear stress, only the torsional shear stress can be offset, while the additional bending normal stress cannot be eliminated, thus lead to large measurement errors due to Figure 5 It can also be seen that, in addition to the influence of the lateral effect and the paste orientation, the main error of the shear force measurement is caused by the inconsistency between the stress state at the center of the strain rosette and the pure shear stress state of the measured point

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