Marine platform ice force measuring device based on local dense strain response

Abstract

The ice force measuring device includes one cylinder with certain flexibility and one strain sensors. The cylinder is mounted onto the casing of marine platform, and can slide up and down along the casing without vertical constraint force. In the inside wall of the cylinder, there are the strain sensors adhered densely in the circumferential and longitudinal directions. Between the cylinder and the casing, soft silicone gel is filled. On two ends of the cylinder, some floating material is installed for the cylinder to float in marine. The cylinder structure can maintain the original geometrical shape of the casing at most and reduce the change caused by the change in geometrical shape of the ice load in the ice facing direction, so that the present invention has the advantages of direct measurement and indirect inversion.

Description

technical field [0001] The invention relates to a measuring device for ice load of an ocean platform structure. Background technique [0002] Ice load is the main control load in the design of oil and gas drilling platforms in the Bohai Sea of ​​my country. There are many factors affecting the ice load, mainly including the physical and mechanical properties of sea ice and the coupling effect between sea ice and platform structure. Some of these factors are very complex, and some are more difficult to analyze theoretically. Therefore, the main means of analyzing the ice load of the platform structure is through experiments, including model experiments and prototype experiments. The general situation is to analyze the ice load data obtained directly from multiple experiments, and then obtain results that can accurately describe the ice load to a certain extent based on some prior knowledge and necessary theoretical analysis. feasible way. Among them, the ice load data obta...

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Problems solved by technology

For solid contact materials, the load measured by the pressure cell will gradually deviate from the true value (lower) as the material stiffness increases; secondly, for the hydraulic and vibrating wire pressure cells, due to the obvious mechanical hysteresis effect, the measured The high-frequency component of the load will be distorted [[Xie Yongli, Wang Xiaomou. Calibration and analysis of resistive micro pressure cells [J]. Journal of Xi’an Highway University, 1993, 13(3): 23~27.], [Chen Zhijian, You Qingshi, Lin Min, Li Tiyan. Application research of vibrating wire pressure cell in stress monitoring of rigid contact surface [J], China Engineering Science, 2002, 4(12): 80~85.]]; The requirements for calibration are relatively high, and the effect of using oil pressure calibration in the laboratory is generally better [Xie Yongli, Wang Xiaomou. Calibration and analysis of resistive miniature pressure cells [J]. Journal of Xi'an Highway College, 1993, 13 (3): 23~27.], but there is a certain difference between this situation and the original stress mode, and the calibration results using sand and soil are often unsatisfactory [Xie Yongli, Wang Xiaomou. About the resistance type micro pressure cell Calibration and analysis of [J]. Journal of Xi'an Highway University, 1993, 13(3): 23~27.]

[0006] In view of the limitations of various measurement conditions, the pressure cells can only be distributed on a limited number of platform legs, and the distribution angle along the legs is also limited, so it is impossible to measure the total and all-round ice force of the platform

Therefore, people try to invert the dynamic total ice force of the platform by using the overall response of the structure (such as acceleration response), but this dynamic load inversion method requires relatively complete and accurate structural parameters such as natural frequency, damping and modulus. state, etc., otherwise the inversion result will have a large error

In addition, when the number of measurement points is limited, the arrangement of measurement points and the accuracy of measurement data have a greater impact on the inversion results

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