Damage Modeling of Weld Structures in Extreme Conditions

Bisong M.S., Lepov V.V., Sivtsev P.V., Golikov N.I., Makharova S.N.

The experimental modelling and numerical analysis of stress-strain state and fracture of low-alloyed welded steel samples test has been considered. The mechanical tests include tension and low-cycling fatigue of small welded steel probes. The mechanical heterogeneity has been estimated by the micro hardness test. The analysis include FEM of stress-strain state of inhomogeneity welded probes and stochastic modelling of cracks coalescence and growth. It has been shown that the stress and strain distribution could not be only criterion for estimation of possible failure places but it is necessary to take into account the inhomogeneity and defects in weld and heat affected zone also. Last ones are responsible for acceleration of damage accumulation and crack growth in steel structures. Thereby for exclude the catastrophic breakdown and failure of complex engineering systems the change of legacy approach to estimation of steel structures and organisation of constant surveillance are recommended. This research is beneficial to welders, modellers of structures, researches as a whole.

Key words: damage, steel welding, heat affected zone, elasticity modulus, microhardness, numerical modelling, FEM, stress-strain state, stochastic modelling, crack, fracture.

Science and Education, 2017, No.3, pp.67-71