Fractional step methods for thermo-mechanical damage analyses at transient elevated temperatures

✍ Scribed by J. Stabler; G. Baker

• Book ID: 101233172
• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 241 KB
• Volume: 48
• Category: Article
• ISSN: 0029-5981
• DOI: 10.1002/(sici)1097-0207(20000620)48:5<761::aid-nme906>3.0.co;2-i

✦ Synopsis

In the interest of computational e ciency this paper describes the implementation of a coupled thermodamage constitutive model into a coupled time-stepping analysis using fractional step methods. To begin it is demonstrated that a thermo-damage model can be presented in a thermodynamic framework with the evolution equations satisfying the ÿrst and second laws of thermodynamics. The equations of evolution are partitioned in two ways, thus deÿning two fractional step methods: an isothermal method and an isentropic method. When implemented into a time-stepping algorithm the isentropic method maintains a precise energy balance for the entire analysis where as the isothermal method can only provide an energy balance at the end of each thermal time step. In addition, a stability analysis shows that the isentropic analysis is unconditionally stable while a isothermal analysis is at best conditionally stable. Simulations of thermal fracture in a restrained specimen under heat show stable growth of damage to failure.