Adjustable Piezoelectric Vibration Device for Wide Frequency Range
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Solution Overview
Problem
Existing piezoelectric excitation systems can only generate a limited range of resonance frequencies, requiring multiple systems to accommodate different test objects, and adjusting natural frequencies is typically done experimentally, lacking efficiency and precision.
Innovation Solution
A device with an adjustable piezoelectric excitation system that couples two masses via a spring with a variable stiffness, allowing for adjustment of natural frequency through changes in the number, size, and material of piezoelectric discs, as well as mass ratios and operating voltage, using a mathematical model to calculate and set desired resonant frequencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a fixed piezoelectric excitation system is used, then the structure is simple, but the frequency range is limited
Solution Approach 1:
The piezoelectric excitation system is designed with adjustable rigidity through variable stiffness elements (such as adjustable springs or flexible connections), allowing the natural frequency to be dynamically changed without replacing the entire system. This enables a single device to cover a wide frequency range by modifying structural parameters rather than using multiple fixed systems.
Solution Approach 2:
The system incorporates parameters that can be changed to adjust the natural frequency, such as varying the stiffness of coupling elements, changing mass distribution, or modifying piezoelectric element configurations. These parameter adjustments allow frequency tuning while maintaining the same physical structure, resolving the contradiction between versatility and complexity.
2Adaptability or versatility
If multiple piezoelectric excitation systems are used to cover different frequencies, then the frequency range is expanded, but the device complexity increases
Solution Approach 1:
A single piezoelectric excitation system is designed to perform multiple frequency functions through adjustable parameters. The system can be configured to generate different natural frequencies by modifying stiffness, mass, or geometric parameters, making one universal device replace multiple frequency-specific systems. This reduces the quantity of systems needed while maintaining broad frequency coverage.
Solution Approach 2:
The excitation system incorporates dynamic adjustment capabilities that allow it to adapt its natural frequency on demand. By using adjustable stiffness elements or reconfigurable structures, the same physical system can serve different frequency requirements, eliminating the need to maintain multiple static systems for different frequency ranges.
3Loss of time
If experimental adjustment is used to set natural frequency, then the system is easy to operate, but the adjustment time increases
Solution Approach 1:
The system incorporates pre-calculated parameter sets or lookup tables that provide the correct stiffness, mass, or geometric configurations for desired natural frequencies. Before operation, the appropriate parameters can be selected based on the target frequency, eliminating the need for time-consuming experimental trial-and-error adjustments during actual use. This preliminary preparation reduces adjustment time while maintaining precision.
Solution Approach 2:
The system includes frequency measurement and feedback mechanisms that monitor the actual natural frequency and provide information for precise adjustment. By measuring the current frequency and comparing it to the target value, the system can make accurate adjustments using feedback control, reducing both adjustment time and improving frequency precision simultaneously.
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 the generation of mechanical vibrations across a wide frequency range with a single device, allowing for precise adjustment of natural frequencies without structural changes, enhancing the efficiency and accuracy of fatigue testing.
Implementation Method 1
Piezoelectric excitation systems are based on the inverse piezo effect and are used in fatigue tests, among other things.
Implementation Method 2
In order to ensure that a test object is excited at a resonant frequency, it is necessary for the vibration generator to also oscillate at the test object's resonant frequency.
Data Source
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AI summary
The invention relates to a device for generating mechanical vibrations. The device comprises a first mass (2), a second mass (3), and a piezoelectric excitation system (1) via which the first mass (1) and the second mass (2) are mechanically coupled to each other, wherein the piezoelectric excitation system (1) has a stiffness. It is provided that the piezoelectric excitation system (1) is designed such that its stiffness is adjustable. The invention further relates to a method for calculating the resonance frequency of a device for generating mechanical vibrations.