Electromechanical Clamp Release for SHPB Stress Wave Synchronization
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Solution Overview
Problem
Conventional split-Hopkinson pressure bar (SHPB) systems face challenges in precisely controlling the release time of mechanical clamps, which can lead to unsynchronized stress wave application during combined loading tests, affecting the accuracy of material deformation measurements.
Innovation Solution
The system employs electromechanical transducers and piezoelectric elements to control the release of clamps, allowing for precise and accurate timing of stress wave application on the test specimen, enabling simultaneous or sequential release of torsional and axial loading waves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If mechanical clamps with mechanical fuses are used to hold loading bars, then the device structure is simple, but the release time cannot be controlled precisely and accurately
Solution Approach 1:
The patent replaces the mechanical fuse-based clamp release mechanism with an electromechanical transducer system. The electromechanical transducers (such as piezoelectric actuators) are driven by electrical signals to control the release timing of clamps with microsecond precision, eliminating the imprecision of mechanical fuse fracturing while maintaining structural simplicity through electronic control.
Solution Approach 2:
The patent changes the control parameter from mechanical force (mechanical fuse strength) to electrical parameters (voltage pulse timing and magnitude). By controlling the electrical signals to the electromechanical transducers, the release time can be precisely adjusted and synchronized, enabling accurate control of stress wave application timing.
2Reliability
If multiple clamps are used for combined loading, then both torsional and axial loading can be applied, but the release times cannot be accurately synchronized
Solution Approach 1:
The patent implements a centralized control system that receives feedback from sensors monitoring the positions and states of multiple clamps. The controller adjusts the electrical signals to electromechanical transducers on each clamp to ensure synchronized release, achieving accurate coordination of torsional and axial stress wave application through closed-loop control.
Solution Approach 2:
The patent uses a universal control architecture where a single controller manages multiple electromechanical transducers across different clamp locations. This multi-functional system can coordinate the release of clamps holding both torsional and axial loading bars, enabling flexible and accurate synchronized control for various combined loading configurations.
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
This approach ensures precise control over the application of combined torsional and axial loading, improving the synchronization of stress waves and enhancing the accuracy of material deformation measurements at high strain rates.
Implementation Method 1
The clamp actuating unit is configured to selectively release the first clamp and the second clamp. In an embodiment, the clamp actuating unit includes at least one piezoelectric element.
Implementation Method 2
A stress wave, compression, tension, or torsion, is introduced into one of the rods (an input bar), which transmits the stress wave to the specimen. This causes the specimen to deform.
Data Source
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AI summary
A system (100) for measuring loading on a test specimen (102). The system (100) includes the test specimen (102) arranged between a first loading bar (104) and a second loading bar (106). The system (100) further includes a first loading unit (112) and a second loading unit (116) configured to apply a first load (114) and a second load (118) to the first and second loading bars (104, 106), respectively. The system (100) further includes a first clamp (120) and a second clamp (130) configured to hold the first and second loading bars (104, 106) against the first and second loads (114, 118), respectively. The system (100) further includes a clamp actuating unit (140) configured to selectively release at least the first clamp (120). The clamp actuating unit (140) further includes a controller (150) configured to electrically actuate at least one first electromechanical transducer (142) from a retained state (P1) to a released state (P2) to release the first clamp (120), such that the first loading bar (104) applies a first loading wave (122) to the test specimen (102).