Hard-shell inclusion strain gauge for 3D stress monitoring
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current sensors fail to accurately monitor the 3D stress evolution and dynamic response of surrounding rocks and structures in underground engineering due to rheological properties of materials, limited structural layout, and inability to collect real-time high-frequency data, posing challenges for disaster warning and seismic design.
Innovation Solution
A hard-shell inclusion strain gauge system with an elastic cylinder and strain rosettes installed in a borehole, using resistance strain gauges and a data acquisition module for real-time monitoring, which includes a photoelectric signal converter and fiber grating demodulator for accurate and stable data collection and analysis.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Duration of action of stationary object
If soft inclusion strain gauges are used for long-term stress monitoring, then the monitoring duration can be extended, but the rheological properties of the shell material cause significant deviation in measurement data
Solution Approach 1:
The patent changes the material parameter of the shell from soft material with rheological properties to hard material with elastic properties. The hard shell maintains its structural integrity and elastic recovery capability over long periods, eliminating the measurement deviation caused by rheological creep while preserving long-term monitoring capability.
Solution Approach 2:
The patent employs a composite structure combining a hard elastic shell with strain gauge sensors. The hard shell provides stable structural support and elastic recovery, while the integrated strain gauges accurately measure the strain, creating a composite monitoring system that maintains both long-term durability and measurement precision.
2Device complexity
If fiber grating strain sensors are used, then the structural layout can be simplified, but they cannot collect 3D stress data in real-time and high-frequency
Solution Approach 1:
The patent integrates multiple strain gauges oriented in different directions (0°, 45°, 90°) within a single hard shell structure, enabling the device to simultaneously measure multi-directional strains and calculate complete 3D stress components. This multi-functional design achieves both simplified structure and high-frequency real-time 3D stress monitoring capability.
3Ease of manufacture
If conventional sensors are used in underground engineering, then the installation process is simplified, but they fail to provide accurate real-time monitoring of dynamic stress evolution
Solution Approach 1:
The patent segments the monitoring function into distinct directional strain measurements using multiple strain gauges arranged at specific angles (0°, 45°, 90°). Each gauge independently measures strain in its specific direction, and the combined data provides comprehensive 3D stress information, enhancing reliability while maintaining installation simplicity through modular gauge placement.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system provides reliable, long-term, high-frequency monitoring of 3D stress, improving measurement accuracy and stability, enabling effective dynamic disaster warning and seismic design by isolating the measuring element and using elastic steel for enhanced durability and precision.
Implementation Method 1
at least three sets of strain rosettes are arranged on the inner wall of the elastic cylinder body
Implementation Method 2
which includes a photoelectric signal converter and fiber grating demodulator for accurate and stable data collection and analysis
Data Source
AI summary
This application relates to a hard-shell inclusion strain gauge for 3D stress in surrounding rockmass of underground engineering. The hard-shell inclusion strain gauge comprises an elastic cylinder and at least three sets of strain rosettes, wherein the elastic cylinder is installed in a borehole of underground engineering, and at least three sets of strain rosettes are equidistant along the circumference on the inner wall of the elastic cylinder. It can accurately measure strain values and variables of each strain rosette through data collection and transmission module, and calculate 3D stress in surrounding rock of underground engineering. It can obtain dynamic long-term monitoring of 3D stress evolution in complex environments of underground engineering, truly reflecting the real-time state, the spatial distribution, and the evolution of 3D stress in rockmass, and provide in-situ basic data for engineering disaster warning and control.