Issue 47

A. Bensari et alii, Frattura ed Integrità Strutturale, 47 (2019) 17-29; DOI: 10.3221/IGF-ESIS.47.02 19 Element (%) C S P Si Mn Ni Cr Mo Cu Ti V SA 516 Gr.70 0.16 0.005 0.013 0.44 1.45 0.08 0.07 0.008 0.038 0.004 0.1 Table 1 : Chemical compositions. Material Mechanical properties Thermal Properties Yield Strength (MPa) Tensile Strength (MPa) Elongation at Break (%) Modulus of Elasticity (GPa) Poissons Ratio Bulk Modulus (GPa) Shear Modulus (GPa) Specific Heat Capacity (J/g-°C) Thermal Conductivity (W/m-K) SA 516 Gr.70 355 485-620 21 200 0.3 160 80 0.44 36.3 Table 2 : Mechanical properties and thermal properties at room temperature. Figure 1 : The variation of properties as a function with temperature. (a) Mechanical properties and (b) Thermal properties. The values of these parameters have been obtained by an extrapolation and interpolation from the extracted values of ASME, the density of the carbon steel was taken as its ambient value of 7850 kg/m3 over the normally experienced temperature range in a building fire [20]. We have been proposed that the poisson ratio remains constant for all temperature values. M ETHODOLOGY OF NUMERICAL SIMULATION ypical examples of simulations using elastic–plastic models are provided by the studies of Bergheau and Leblond [11, 12]. In contrast, few simulations have used elastic–viscoplastic models. The reason why elastic-viscoplastic effects are disregarded in most welding simulations is that the duration of welding processes is quite short, so that it is generally thought to be insufficient for significant creep to occur. In the present study, a thermal elastic-plastic finite element procedure was employed to simulate the thermo-mechanical response of welding problem. The specimens used in this study are plates of 150 mm in length and 15 mm in thickness for the two types of chamfers; X-Groove and V- Groove with four passes as mentioned in Fig. 2. The two different weld specimens were analyzed using the Abaqus AWI 2D Graphical User Interface (GUI) plug-in. The weld specimens were produced by a mechanised computer-controlled welding system, which adjusted the speed, feed and energy across the specimens. The FE models were rapidly constructed using the AWI plug-in in Abaqus/CAE. The 0 200 400 600 800 1000 1200 1400 1600 -50 0 50 100 150 200 250 300 350 400 Yield Strength (MPa) Ultimate Strength (MPa) Modulus of Elasticity (GPa) Temperature (°C) a ) -50 0 50 100 150 200 250 300 350 400 450 500 550 -25 0 25 50 75 100 125 150 175 200 225 250 0 200 400 600 800 1000 1200 1400 1600 1,0E-05 1,2E-05 1,4E-05 1,6E-05 1,8E-05 2,0E-05 2,2E-05 2,4E-05 2,6E-05 Coefficient of Thermal Expansion (μm/m-°C) Specific Heat (mJ/Tonne/°C) Conductivity (W/m.K) Temperature (°C) 4E+08 5E+08 6E+08 7E+08 8E+08 9E+08 1E+09 1E+09 -5 0 5 10 15 20 25 30 35 40 b ) T