Composite Structure Damping Detection via Wave Propagation
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Solution Overview
Problem
Current methods for determining local material damping in composite structures, particularly in high-mechanical-load components like missile skins, are time-consuming, labor-intensive, and prone to errors due to the need for multiple sensor positions and potential interference with the material being measured.
Innovation Solution
A method utilizing detunable, quasi-static mechanical vibrations to assess damping properties with high spatial and directional resolution, employing adaptive actuators like piezoelectric materials to generate vibrations and measure changes in wave crests, allowing for non-invasive, online monitoring of damping changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors are positioned at various points to measure material attenuation, then measurement precision is improved, but loss of time increases due to the need to change sensor positions
Solution Approach 1:
The patent applies the dynamics principle by making the sensor position variable through actuator-induced wave propagation. Instead of physically moving sensors to different locations, the method dynamically changes the wave propagation path and measurement location through controlled actuation, enabling rapid sequential measurement at multiple positions without physical sensor relocation.
Solution Approach 2:
The patent uses copying by creating virtual measurements through wave propagation simulations. Multiple measurement points are effectively copied through the propagation of wave patterns through the structure, allowing the system to obtain data from multiple locations simultaneously or in rapid succession without physically placing sensors at each point.
2Measurement precision
If multiple sensors are used to measure local attenuation, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent applies universality by making a single sensor capable of performing multiple measurement functions at different locations through actuator-induced wave propagation. The same sensor can measure material damping at various positions sequentially, eliminating the need for multiple dedicated sensors and reducing overall system complexity.
Solution Approach 2:
The patent uses copying by creating virtual measurement copies through wave propagation. Instead of physically duplicating sensors at multiple locations, the system copies the measurement capability through controlled wave patterns, allowing one physical sensor to effectively become multiple virtual sensors.
3Measurement precision
If sensors are placed close to the material being measured, then measurement precision is improved, but object-generated harmful factors increase due to sensor interference
Solution Approach 1:
The patent applies the intermediary principle by introducing wave propagation as a mediator between the sensor and the material damping characteristics. Instead of direct contact measurement that causes interference, the wave acts as an intermediary carrier that transports damping information from the material to the sensor without requiring physical proximity that would cause interference.
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
Enables efficient, low-interference, and accurate localization of damping attenuation, detecting progressive crack growth and material changes without destructive testing, reducing inspection downtimes and improving the reliability of damage diagnosis.
Implementation Method 1
employing adaptive actuators like piezoelectric materials to generate vibrations
Implementation Method 2
This method is based on the principle of wave propagation
Implementation Method 3
Material damping refers to the energy dissipation caused by local and temporal variations in the viscoelastic matrix material
Data Source
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AI summary
The method involves measuring generated oscillations (5, 6) in a lightweight construction component (1), and producing attenuation in the material to be tested with local and directional resolution, where material of the lightweight construction component is made of plastic material such as carbon fiber-strengthened plastic material and glass-fiber reinforced plastic material. A corporate value of a sensor (4) is evaluated by a computational device, and the location, direction and/or the intensity of damage to the material to be tested in or on the lightweight component is calculated.