The rheological model of uniaxial strain of material with the temperature-dependant functional material constants is proposed. The processing of experiment data obtained from papers and publications is performed on the basis of strengthening law and a creep model with initial strain rate. Stress functions for initial strain rate and steady-state strain rate are assumed to be power functions. Dependences of material constants from temperature are assumed to be exponent functions. The physical equations of integral internal forces for a tension-bending rod are elaborated. A quasilinear analogue of the equations with variable transverse stiffness properties is also proposed. The quasilinear equations are proved to be convenient for generation of frame rod structure flexibility matrix. The calculation of strain state creep properties at a given time consists of two independent calculations. The first calculation is essential for evaluating the initial strain rate, and the second calculation is required for evaluating the steady-state strain rate. Both calculations are performed with the identical set of equations. An example of evaluation of tension-bending rod strain state under high temperatures is provided.