Development of constitutive laws for materials processing and engineering design
One key topic which is very close to the heart of all material scientists is the accelerated innovation of new age materials with exceptional physical and mechanical properties. However, despite the quantum increase in research efforts, the overall acceleration has been incremental. This is because, the response of the material in service condition is a complex phenomena and depends upon several variables which vary both in time (monotonic, cyclic) and length scale (atomic constituents, dispersoids). As a result, more often than not, we have to fall back upon the well-established materials. However, to meet the modern-day requirements, the existing materials are subjected to wide range of loading environments where the materials response has not been measured previously. This presents a difficult challenge as these complicated experimental set-ups and study require significant amount of manpower, energy and costs. Nevertheless, significant savings can be made if we manage to increase the predictive capabilities of our material constitutive model beyond the measured range.
We at Experimental and Computational Materials Mechanics lab would like to develop reliable constitutive modelling framework for several important class of Al alloys based on the principles of thermally activated mechanisms of plastic deformation. We expect our modelling framework to predict the material behaviour accurately over a wide range of temperature, strain rate and strain. The development of modelling framework is challenging considering that there are several regimes in Al alloys where the dominant deformation mechanism is different. For example, dynamic strain ageing with negative strain rate sensitivity, solute drag effect and dynamic recovery effects are commonly observed in Al alloys. Moving forward, we aim to integrate the constitutive modelling framework in a finite element environment, so that we can tailor the existing metal processing routes for improved efficiency and also aid the design process of structural components.
Projects:
- Development of constitutive modelling framework based on mechanical threshold stress model for hot stamping and warm forming conditions.
- Development of a physics-based material model for creep age forming of age hardenable Al alloys.