STRESSES AND DEFORMATIONS IN OVERLAPPED DIESEL-ENGINE CRANKSHAFTS PART 2 - EVALUATION OF RESULTS

The extensive results presented in Part 1 (in the previous issue) hav e been supplemented and analysed further. A large number of cross-sect ions which could be reasonably used to calculate nominal stresses has been listed and evaluated. An inclined (flat, rectangular) section thr ough the web is shown to be the best to calculate nominal stresses due to torsion, pure radial bending and bending due to crankpin forces; i ts width is h (see Fig. 1), the length of the shortest line joining cr ankpin and journal fillets in the plane of symmetry. Stress concentrat ion factors based on these nominal stresses show only modest scatter f rom single curves for crankpin and journal fillets for torsion and rad ial bending. Predictions using the most commonly used method underesti mate shear stresses due to torsion and overestimate bending stresses.