The very first step when starting an experimental modal analysis project is the definition of the geometry used for visualization of the resulting mode shapes. This geometry includes measurement points with a label and corresponding coordinates, and usually also connections and surfaces to allow a good visualization of the measured mode. This step, even if it sounds straightforward, can be quite time consuming and is often done in a rather approximate way. Photogrammetry is a technique that extracts 2D or 3D information through the process of analyzing and interpreting photographs. It is widely used for the creation of topographic maps or city maps, and more and more for quick modeling of civil engineering structures or accident reconstruction.The purpose of this paper is to evaluate the use of this technique in the context of modal testing of automotive structures. After a short description of the method, the approach will be evaluated with regard to several criteria: accuracy, convenience, cost, required time. Two cases will be shown: the measurement of an exhaust, on which the measurements will be compared with a classical coordinate measurement machine and the measurement of a body in white, for which the measured points will be correlated with points of an FE model.The study will show that photogrammetry is indeed an interesting approach to measure the geometry. The main benefits are the increased accuracy compared to manual measurements, short immobilization time of the object, simplicity, enhanced visualization and low cost.
Measuring a Geometry by Photogrammetry: Evaluation of the Approach in View of Experimental Modal Analysis on Automotive Structures
Sae Technical Papers
SAE 2001 Noise & Vibration Conference & Exposition ; 2001
2001-04-30
Conference paper
English
Photogrammetry-Based Experimental Modal Analysis for Plate Structures
British Library Conference Proceedings | 2021
|Experimental modal analysis of automotive exhaust structures
Automotive engineering | 2001
|Experimental Modal Analysis of Automotive Exhaust Structures
SAE Technical Papers | 2001
|2001-01-0662 Experimental Modal Analysis of Automotive Exhaust Structures
British Library Conference Proceedings | 2001
|Experimental Modal Analysis on Automotive Development
SAE Technical Papers | 2003
|