On May 12, the "20th Nonlinear Vibration and the 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.
Qianyanlang Scientific Instruments was invited to attend the conference with its independently developed high-speed camera, digital image correlation DIC measurement system, and particle image velocimetry PIV system, and demonstrated classic applications in the field of nonlinear vibration to the experts and scholars attending the conference.
Vehicles such as airplanes and automobiles 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.
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 extrusion 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 the speed bump, the strain distribution of key parts such as the tire tread blocks and sidewalls is calculated, providing a basis for the structural optimization design of the tire.
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.
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 be used to 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.
The earthquake simulation experiment mainly simulates the excitation source of earthquake randomness through a vibration table, and uses a high-speed camera and a DIC strain measurement system to capture the image sequence of the structural damage evolution process. By applying a speckle pattern on the surface of the model, the displacement, strain, and vibration mode of each point of the structural component under the random excitation source are measured in real time, thereby evaluating the damage and failure mechanism of the model building under earthquake action.
In the vibration research of micro-nano structures such as friction electric nanogenerators (TENGs), high-speed cameras are used to capture the vibration transient 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-nanostructure design and improve key performance.
Revealer 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 my country.
