 Register   #### TEST CASE 12.1 CALCULATION OF TEMPERATURE FIELD OF PRISMATIC BAR AT VARIOUS HEAT LOADS

Reference:

Numerical solution (Abaqus).

Problem description:

Heat flux Q influences at bottom side of a steel prismatic bar. T is a time-varied temperature of the top side of prism. Convective heat-exchange interacts at lateral sides of the bar, external environment temperature is T0. Initial temperature of the bar is 20 °С. Varying of heat flux Q and temperature T during time is shown at figure below. Determine temperatures T1, T2, T3 at points A and B. Find also vertical displacements w1, w2, w3 at point A at time t1 = 100 s, t2 = 250 s, t3 = 500 s respectively.

Problem sketch: Type of created problem:

Spatial structure (X, Y, Z, UX, UY, UZ).

Geometry properties:

L = 300 mm; a = 30 mm.

Material properties:

Elastic modulus: E = 2·1011 Pa;

Poisson’s ratio: µ = 0.3;

Density: ρ = 7850 kg/m3;

Expansion coefficient: α = 1.2·10-5 1/°С;

Conductivity: λ = 60.5 W/(m·°С);

Specific heat: С = 434 J/(kg·°С);

Heat transfer coefficient: β = 45 W/(m2·°С).

Boundary conditions:

At bottom side of bar: Z = 0;

Symmetry boundary conditions;

Heat-exchange between bar and external environment is modeled via plate of surface heat transfer.

Model description:

System is modeled using 270 8-noded solid FE (FE type is 36) and 180 plates of surface heat transfer (FE type is 164). Due to symmetry, only quarter of bar with corresponding boundary conditions is considered. Dynamic calculation with heat exchange is performed (full time is 500 s, step time 0.5 s).

Calculation results:

 Target value Abaqus solution LIRA 10 Deviation, % T1,А, °С 800.0 800.0 0.00 T1,В, °С 26.6985 26.772 0.26 T2,А, °С 800.0 800.0 0.00 T2,В, °С 47.9537 47.905 0.11 T3,А, °С 20.0 20.0 0.00 T3,В, °С 63.6868 63.521 0.26 w1, mm 0.3671 0.373 1.60 w2, mm 0.6206 0.624 0.54 w3, mm 0.2444 0.244 0.16 Bar temperature distribution at time t1, °С Bar temperature distribution at time t2, °С Bar temperature distribution at time t3, °С Vertical displacements of bar at time t1, mm Vertical displacements of bar at time t2, mm Vertical displacements of bar at time t3, mm