METHOD AND DEVICE FOR CALCULATION OF AXIAL METAL CONSTRUCTION LOADING Russian patent published in 2012 - IPC G01L1/00 

FIELD: metal construction control.

SUBSTANCE: software is used to detect rods with the highest load. The rod's own lateral decreasing oscillations are induced and registered in two points. Own frequencies are measured with the use of Fourier analysis of registered records. The value of the longitudinal axial load on the rod is calculated through the frequency ratio with the consideration of formulas denoting the correlation of own frequencies and fixation conditions and the value of longitudinal stretching force or compression force. It is compared with the design load and the critical load, and the ratio of the loads for all inspected rods with the highest load is used to determine the technical condition of the engineering structure. The device comprises a mallet used for mechanical own decreasing oscillations inducement, two high-frequency speed or acceleration sensors, a two-channel analogue amplifier with sixth order Butterworth filters, a 16-digit AD converter, 1 Mb RAM, a display device, an input device for information concerning the inspected rods and the engineering construction, an output device for certain frequency or inspected rod loading values, a power source and a microprocessor. The device is portable, it has control and registration software, software for signal processing which includes: Fourier calculations and defining own oscillation frequency of the inspected rods, calculating and the value of longitudinal stretching force or compression force based on own oscillation frequencies and assessment of the loading value of the rods.

EFFECT: figures for stretching force and compressing force applied to the axial construction rod in normal working conditions can be determined; rods loading value assessment.

4 dwg, 1 tbl