Project Background
In applied mechanics and many engineering fields, the measurement of displacement fields, strain fields, and stress fields is of great significance. With the continuous improvement of requirements for testing environments and testing accuracy, traditional contact - type measurement methods at finite points face significant limitations. The most commonly used contact - type strain measurement methods, such as strain gauges and piezoelectric sensors, can only obtain strain data at discrete points. For lightweight structures, they will also introduce additional mass effects. Non - contact measurement methods, such as photoelasticity, X - ray diffraction, digital image correlation, and holographic interferometry, have applications in specific scenarios. The development of laser Doppler vibration measurement technology provides a new solution for non - contact full - field dynamic stress and strain measurement. This article will use the Sunnyinnovation Scanning Laser Doppler Vibrometer to measure surface vibration information and combine it with post - processing algorithms to achieve high - resolution dynamic surface strain and stress evaluation.
Test Object
The beam is a simple structure. Its advantage is that the exact stress - strain distribution can be obtained through theoretical calculations, and its performance is easy to describe from the perspectives of experiments and models. In this test, an aluminum symmetric cantilever beam of model 6061 is used as the test object. A shaker is used to apply a sinusoidal excitation load of 10Hz - 10kHz to the fixed end of the beam.
Test Object
Test Equipment
LV - SC400 Laser Scanning Vibrometer
Sunnyinnovation optical intelligence Laser Scanning Vibrometer LV-SC400 can measure the vibration of the structure surface through high - speed scanning galvanometers, thereby obtaining real high - resolution displacement and deformation data. Then, the corresponding strain can be calculated through the Sunnyinnovation Modal Analysis Software.
Test Results
The test area is 40mm in the horizontal direction and 70mm in the vertical direction. The measuring points are arranged in a 6×31 pattern, with a total of 186 measuring points. The displacement information of each measuring point can be quickly obtained through scanning.
Layout of measuring points
After measuring the displacement data of the measuring points at a certain moment, the full - field strain data and stress data at the current moment can be obtained through the stress - strain post - processing software.
Strain picture
Application Prospects
By using a scanning laser vibrometer to measure the vibration of a structure and conduct stress - strain analysis, the areas with the largest strain and stress in the structure can be determined. Thus, it is possible to predict the positions in the structure that are most likely to experience failures or serious damage due to resonance. The dynamic strain distribution can also provide high - precision measurement data for fatigue tests, which is of great significance for improving structural design and ensuring the safety and reliability of structures.
About SunnyInnovation Optical Intelligence Corporation Limited
Established in 2008 as a technology subsidiary of Sunny Optical Corporation Ltd in Yuyao, Zhejiang, China, SunnyInnovation is engaged in the development of laser Doppler vibrometers for vibration measurement and technical service in solutions for product design and optimization concerning the vibration. SunnyInnova has faithfully served China’s universities, research institutes, industrial R&D centers, and infrastructure operators with sophisticated and competitive laser vibrometers for vibration measurement with mechanical, civil, transportation, medical, energy, aerospace, biological, healthcare, sports, and many structures and objects. According to leading market research and advisory firms, SunnyInnova has remained the leading brand in China’s overall laser Doppler vibrometer product market for 10 consecutive years (2014-2024) in terms of products and unit shipments. In recent years, SunnyInnova has focused on the development of advanced vibrometers for scanning, MEMS, and mode shape generation to support the demands from research and product development efforts related to vibration measurement, control, utilization, and optimization with broad industries and technical services. The laser vibrometer products won the First Prize of Ningbo Science and Technology Awards and the Second Prize of Zhejiang Science and Technology Advancement Awards. SunnyInnova has also been collaborating with Tsinghua University, Peking University, Zhejiang University, and many institutions on important research projects with the utilization of laser vibrometers for measurement and analysis under special circumstances using creative functions, further demonstrating SunnyInnova's vibrometer products and solutions have gained recognition in the key sectors of market. For further information, please visit www.sunnyinnova-ldv.com.