Hiroshi Nyuko

STRESS INTENSITY FACTOR FOR TRANSIENT THERMAL STRESSES IN AN INFINITE ELASTIC BODY WITH AN EXTERNAL CRACK

Abstract This paper deals with a transient thermal stress problem in an infinite body with an external crack. The elastic medium is cooled by time- and position-dependent temperature on the external crack. It is very difficult to obtain the analytical expression for the temperature, so the finite-difference method is used with respect to a time variable. Thus, the analytical expression for the temperature with respect to the spatial variables may be obtained. The temperature solution reduces to a dual-integral equation for spatial variables by use of the finite-difference method for a time variable. The numerical results for stress intensity factor are obtained.

THERMAL-STRESS PROBLEMS IN INDUSTRY. 3: TEMPERATURE DEPENDENCY OF ELASTIC MODULI FOR SEVERAL METALS AT TEMPERATURES FROM -196 TO 1000° C

The temperature dependency of the dynamic moduli of elasticity of steel and aluminum and copper alloys was investigated experimentally by an ultrasonic-wave method, in the temperature range from —196 to 1000°C. The results are compared with those obtained by the resonant-frequency method and are represented as empirical formulas. Useful data for commercial alloys are given in tables, by chemical composition.

Thermal shock problem of a hollow circular cylinder with a crack

Abstract This paper deals with the thermal shock problem of an infinitely long, hollow, circular cylinder with an edge crack on the outer surface, initially at uniform temperature, being suddenly cooled on the circular surface. It is assumed that the thermal disturbance near the crack tip may be neglected. The transient thermal stress problem of the elastic solid with a crack is analyzed and the stress intensity factor at the crack tip determined. Simplified formulations of the nondimensional maximum transient stress intensity factor as a function of Biots number, the nondimensional crack length, and the ratio of the inner radius to the outer radius are proposed.

Stress intensity factor for transient thermal stresses in an infinite elastic solid containing an annular crack

SummaryThe present paper treats the transient thermal stress problem in an infinite, isotropic solid containing an annular crack. The elastic medium is cooled by time and position dependent temperature on the annular crack surface. It is very difficult to obtain the analytical expression for the temperature so that we use the finite difference method solely with respect to a time variable. Thus, the analytical solution for the temperature with respect to the spatial variables reduces to a dual integral equation. Results for the stress intensity factors are obtained numerically.übersichtUntersucht werden die transienten WÄrmespannungen in einem unendlichen elastischen Körper, der einen ringförmigen Ri\ enthÄlt. Das elastische Medium wird durch eine zeit- und ortsabhÄngige Temperaturverteilung auf der Ri\oberflÄche gekühlt. Da es schwierig ist, eine analytische Lösung für die Temperatur anzugeben, wird bezüglich der Zeit die Finite-Differenzen-Methode angewandt. Dann kann bezüglich der Ortskoordinaten eine analytische Lösung für die Temperatur in Form einer dualen Integralgleichung angegeben werden. Die SpannungsintensitÄtsfaktoren werden numerisch berechnet.

THERMAL SHOCK PROBLEMS OF ELASTIC BODIES WITH A CRACK

This paper deals with thermal shock, problems of elastic bodies with a crack. The case considered is that of an infinitely long circular cylinder with an edge crack, and a homogeneous flat plate with an edge crack initially at uniform temperature and suddenly immersed into a medium of lower temperature. The thermal disturbance near the crack tip is assumed to be neglible in the analysis of the temperature field because thermal shocks occur very quickly. We analyze the transient thermal stress problems of elastic solids with a crack and determine the stress intensity factor at the crack tip. The nondimensional maximum transient stress intensity factor is expressed as a function of the Biot number and the nondimensional crack length. Then we propose simplified formulations of the nondimensional maximum transient stress intensity factor as a function of the Biot number and the nondimensional crack length.

Thermal Shock Problem of a Hollow Circular Cylinder with a Crack

This paper deals with the thermal shock problem of a hollow circular cylinder with an edge crack, initially at uniform temperature, being suddenly cooled on the circular surfaces. It is asuumed that the thermal disturbance near the crack surface may be neglected in the analysis of the temperature field of the elastic solid with a crack, because thermal shock occurs rapidly. We analyzed the transient thermal stress problem of a hollow circular cylinder with a crack and determined the stress intensity factor at the crack tip. The nondimensional maximum transient stress intensity factor is expressed as a function of Biots number and the nondimensional crack length. We then proposed a simplified formulation of the nondimensional maximum transient stress intensity factor as a function of Biots number and the nondimensional crack length.

Transient thermal stress in an infinite elastic solid containing an annular crack.

The present paper seeks to solve the transient thermal stress in an infinite, isotropic solid containing an annular crack. It is assumed that the transient thermal stress is set up by the application of the heat exchange by convection on the crack surface. By use of the finite difference method for only the time variable the analytical solution for spatial variables can be obtained. The numerical results are shown for the temperature and stress intensity factor.

Transient thermal stress in an infinite elastic solid with an external circular crack.

The present work tackles the transient thermoelastic problem for an infinite solid with an external circular crack. It is assumed that the transient thermal stress is set up by the application of heat exchange by convection on the crack surfaces. By use of the finite difference method for the time variable only, the analytical solution for spatial variables can be obtained. The numerical results are shown for the temperature and stress intensity factor.