On the Stress Intensity Factor of Cracked Beams for Structural Analysis

In this paper simple engineering methods for a fast and close approximation of stress intensity factors of cracked beams and bars, subjected to bending moment, normal and shear forces, as well as torque, are examined. As far as the circular cross section is concerned, comparisons are made on the base of numerical calculations. The agreement between the present results and those previously published is discussed. New formulae for calculating the stress intensity factors are proposed

Mechanical waves in simply and multiply connected thin-walled beams

In this work, a semi analytical finite element (SAFE) formulation aimed at predicting the stress waves existing in thin-walled waveguides of arbitrary cross-section is proposed. To this purpose, a SAFE shell element, in which the in-plane and the out-of-plane behaviours are coupled, is developed and used to build the guided wave equation by simply interpolating the cross-section mid line. For thin-walled waveguides, the derived SAFE formulation allows enormous computational time and memory needs saving with respect to schemes based on SAFE volume elements. The formulation has been applied to predict the dispersive waves in a beam with simply and multiply connected square cross-section

MALIGNANT SCHWANNOMA IN THE POSTERIOR TIBIAL NERVE

Our group have studied a patient affected by a malignant schwannoma in the posterior tibial nerve. Schwannomas are uncommon neoplasms that originate from the Schwann cells of the peripheral nerves: the most common forms are benign. Malignant transformation is rarer. The therapy is surgical and the operation undertaken, if possible, should be the amputation. Alternatively, where amputation is not possible due to the specific localisation or due to patient refusal, the alternative must be the largest and most radical excision possibl