Research project: The Virtual Fields Method
The Virtual Fields Method (VFM) is a method to extract mechanical parameters from full-field deformation maps obtained by imaging.
The Virtual Fields Method (VFM) is a method to extract mechanical parameters from full-field deformation maps obtained by imaging.
It was invented by Professor Michel Grédiac during his PhD in the late 80’s. I have started working on this in the mid-90’s in close collaboration with Prof. Grédiac. I have been dedicating most of my research effort to developing this technique over the years and am now the leading figure at the international level on this topic.
While this research raised very limited interest in the scientific community at the beginning, the last five years have seen it booming, as confirmed on Figure 1. It is on its way to become a standard technique in the next few years.
What does the Virtual Fields Method do?
Figure 2 explains it in a nutshell. While the standard testing techniques currently in place in industry and academia mainly rely on simple uniaxial mechanical tests, the VFM deals with more complex test configurations leading to non-uniform states of deformation. Therefore, instead of performing multiple uniaxial tensile tests in different directions, it is possible to obtain the same directional information from a single more complexly shaped specimen, as illustrated in Figure 2 for composite materials. Figure 3 shows an example of such tests from which all stiffness components of a unidirectional composite can be retrieved. The Virtual Fields Method has been applied to many materials and situations in the past (static/dynamic, composites, metals, foams, wood, polymers etc.), for linear and non-linear behaviour.