On May 12, the "20th Nonlinear Vibration and 17th National Nonlinear Dynamics and Motion Stability Academic Conference" was successfully concluded in Nanning, Guangxi. The conference focused on key topics such as vehicle dynamics and control, fluid-structure coupling vibration, dynamics and experimental technology, random vibration and random dynamics, and micro-nanostructure vibration.
Revealer's Scientific Instruments was invited to attend the conference with its independently developed high-speed cameras, digital image correlation DIC measurement systems, and particle image velocimetry PIV systems , and demonstrated classic applications in the field of nonlinear vibration to the experts and scholars attending the conference.
Application Area 1—Vehicle Dynamics and Control
Aircraft, cars and other vehicles generate nonlinear vibrations under various complex excitations during operation. Studying the vibration characteristics of key parts such as the body and wings can evaluate the performance and comfort of the vehicle and help optimize the dynamic design of the vehicle.
The Revealer high-speed camera captures the local deformation of the car tire when it passes over the speed bump at thousands of frames per second, including the squeezing details of the tire tread blocks. The frequency and period of the tire vibration are calculated by processing and analyzing the captured sequence of images.
The DIC strain measurement system can perform full-field strain measurement on the tire surface. By applying a speckle pattern on the tire surface and then using a high-speed camera to capture a sequence of images of the tire passing over a speed bump, the strain distribution of key parts such as the tire tread blocks and sidewalls can be calculated , providing a basis for the structural optimization design of the tire.
Application direction 2 — Fluid-structure interaction vibration
The interaction between fluid and solid structures such as bridges and wind turbine blades can cause vibration. The PIV flow field measurement system is used to measure the velocity and vorticity changes of the wind flow field around the bridge, and the vibration of the bridge is recorded using a high-speed camera . Combining the data of the two, the interaction mechanism between the wind flow field changes and the bridge vibration can be analyzed, and anti- vortex measures can be added to the bottom of the leading edge and trailing edge of the bridge to reduce the impact of vortices and improve the safety of bridge design.
Application Area 3 — Dynamics and Vibration Experimental Technology
Under the action of airflow, the wing may experience first-order bending vibration, second-order bending vibration and torsional vibration. These multiple-order vibration modes may exist simultaneously or be coupled with each other. High-speed cameras can clearly capture the displacement changes of the wing at different vibration orders. Through image sequences, the frequency, amplitude and phase parameters of different vibration modes can be determined.
Application Area 4 — Random Vibration and Random Dynamics
The earthquake simulation experiment mainly simulates the random excitation source of the earthquake through a shaking table, uses a high-speed camera and a DIC strain measurement system to capture the image sequence of the structural damage evolution process, and applies a speckle pattern on the model surface to measure the displacement, strain and vibration mode of each point of the structural component under the random excitation source in real time, thereby evaluating the damage and failure mechanism of the model building under the action of the earthquake.
Application Area 5 — Micro-nanostructure Vibration Research
In the vibration research of micro-nano structures such as triboelectric nanogenerators (TENGs), high-speed cameras are used to capture the transient vibration images of TENGs under different tensile strains, revealing the dynamic relationship between vibration frequency, amplitude and contact area, and providing a basis for optimizing energy collection efficiency. The DIC measurement system quantitatively characterizes the local strain distribution of composite materials through full-field strain measurement, providing support for R&D personnel to optimize micro-nano structure design and improve key performance.
Conclusion
Revealer's high-speed camera, DIC strain measurement system and PIV flow field measurement system, with their high temporal and spatial resolution and multi-field coupling analysis capabilities, provide experimental data support for the improvement of nonlinear vibration theory, the innovation of control technology and the expansion of engineering applications, and promote the continuous development and innovation of research in the field of nonlinear vibration in China.
