Constitutive Behavior of AA7475-T7351 at High Strain Rate and Elevated Temperatures

Abstract

The use of Aluminum alloys in the aerospace and defence industries has been rapidly increasing in the last few decades, due to their high strength-to-weight ratio and high fracture toughness. Mechanical behavior of aluminum alloys at high temperature and under high strain rate need to be investigated thoroughly to predict the response of structural members under extreme types of loading conditions like crash, impact, etc. In this chapter, the mechanical behavior of AA7475-T7351 alloy is investigated at elevated temperatures under quasi-static and high strain rate conditions. The present work is carried out using two distinct setups for loading the specimens quasi-statically and dynamically at a wide range of temperatures. Cylindrical tensile specimens made of AA7475-T7351 were evaluated under a quasi-static (tensile loading) condition on an electromechanical universal testing machine (10⁻⁴–10⁻¹ s⁻¹) subjected to a temperature range 25–250 °C. While Split Hopkinson Tensile Pressure Bar technique is utilized to obtain the mechanical behavior in the high strain rate range of 500–1500 s⁻¹ at room temperature. Johnson-Cook constitutive model parameters were evaluated from the experimentally obtained stress-strain data. The flow stress prediction ability of this phenomenological model is compared with the experimental result in terms of average absolute error and correlation coefficient.