Determination of the stress concentration factor (K_t) in a rectangular plate with a hole under tensile stress using different methods

Abstract

The stress concentration factor in a plate with a hole is very important for joints. There are many different types of joints and forms. Plates are usually connected with bolted, riveted and pin joints. Connection parts need to consist of hole/holes to make a joint using these machine elements. Machine parts are exposed to different stresses. In this study, the stress concentration factor in a plate with a circular hole under axial tension stresses was invegistated. The emprical (Peterson's) stress concentration factor (Kt) was compared with the results of analytical model, regression analysis (REGA), finite element analysis (FEA), artificial neural network (ANN) model. The stress concentration factor (Kt) was modeled using 5 different methods and the accuracy of Peterson's model was tested. The best results were obtained using ANN model. The emprical results and ANN predictions were compared by using statistical error analyzing the absolute fraction of variance (R2 = 0.999999788), root mean square error (RMSE = 0.000934125) and mean error percentage (MEP = 0.033902049) with the test data. ANN model can be used instead of Peterson's model. Kt was determined by the ANN with an acceptable accuracy.

Application of DIC Method in the Analysis of Stress Concentration and Plastic Zone Development Problems

“…The cutouts of various shapes, such as circular, rectangular, triangular, etc., often occur in the structural elements [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 32 ]. They may be used to reduce the weight of the object or to provide access to a certain part of the device or structure during its operation.…”

“…The option in the case of finite panels is the use of the FEM solutions [ 21 , 22 , 23 ] or the finite-width correction factor [ 19 ]. The value of the finite-width correction factor is given in Table 4 and the SCF can be calculated as: where is given in Equation (3).…”

“…The results for openings of circular, elliptical, rectangular, or triangular shapes were of the primary interest, and the influence of their spatial orientations on the results was also studied [16,22,68]. These pure mathematical formulas and solutions concerning the stress concentration assessment are usually complex and their applications are rather limited [19,23]. The above-mentioned solutions usually give unreal values for the real structural elements with finite size and dimensions and the suitable finite width correction factors should be introduced in practical use [16].…”

“…On the other hand, machine or structure design for several years has become a compromise between the cost and time spent on designing. The contemporary designed structural machine elements are increasingly complex and may include certain shape modifications, e.g., holes or openings [ 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ]; grooves, shoulders, and undercuts [ 26 , 27 , 28 , 29 , 30 , 31 ]; threads [ 10 ]; keyways [ 9 ]; welded connections [ 13 , 32 ]; etc. Such disturbance of the geometry disrupts the flow of the internal forces and causes the local high-stress occurrence, which is sometimes several times higher than the nominal stress calculated with simple basic formulas [ 33 , 34 , 35 ].…”

“…One of the most popular recommendations for the designing process is the Engineering Sciences Data Unit (ESDU—homepage with software and formulas for designing) [ 77 ], which brings proved and validated methods for designing and covers a wide range of disciplines. The common alternative for the above-given approaches became the numerical methods [ 21 , 23 ]. In this area, the Finite Element Method (FEM) became the leading one.…”