Symmetric loading of a Griffith crack by transient concentrated forces in an orthotropic material

Abstract

Body forces are used to model the effect of fasteners and stiffeners. This paper contains results of a study that was undertaken to examine the effect of symmetric impact loading by concentrated body forces on a Griffith crack located in an orthotropic material. The integral transform method along with certain potential functions was used to obtain expressions for the stress intensity factor (SIF). Four different loading cases were considered. Numerical calculations show the typical overshoot in the dynamic SIF reaching values as much as 22% of the corresponding static SIF. The magnitude of the overshoot is affected by the material properties as well as the relative position between the crack and the body forces. In fact as the distance between the application of the body force and the crack increases, the magnitude of the peak value decreases. In addition, as the relative distance increases, the time at which the peak value of the overshoot occurs increases. Furthermore, the time interval over which the overshoot is maintained increases as the relative position increases. The results of the study imply that for stiffened or fastened orthotropic materials, the location of the fasteners or stiffeners may significantly affect the stress intensity factors.