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Issues related to the stress analysis of non-standard flanges. Author: Jiang Hongbo. QQ: 469487338. Feel free to join the discussion group: 369290150. For those who are beginners, it is best to create a complete model for the stress analysis of flanges; such a model should include two paired flanges, as well as gaskets, studs, and nuts. The focus of our discussion here is the issue of stress limits during stress assessment; therefore, we simplify the model. The preload required for flange sealing is calculated using SW6； The dimensions of the two flanges are as follows: Figure 1 The connection structure parameters of the lower flange and the shell Figure 2 The connection structure parameters of the upper flange and the shell were modeled with Solidworks and imported into ansysworkbench 16.0. The material parameters are as follows: Mechanical property parameters of materials under calculated conditions Material temperature ℃ Elastic modulus E Poisson's ratio ν Allowable stress yield strength S30408 forging 20 186 (GPa) 0.3 137 MPa 205 MPa 200 183 (GPa) 0.3 96MPa 144 MPa S30408 plate 20 186 (GPa) 0.3 137 MPa 205 MPa 200 183(GPa) 0.3 130MPa 144 MPa The three-dimensional models of the upper and lower flanges are as follows: Using solid186 units for meshing: Figure 3 Mesh division modelFig 4 Mesh division model set boundary conditions as follows: Figure 5 Boundary setting and load loading Figure 6 Boundary setting and load loading Then the solution is as follows: Figure 7 Stress cloud diagram Figure 8 Stress cloud diagram Here we only make the following linearization path for dangerous sections.: Figure 9 Path1 roadmap Figure 10 Equivalent stress on the linearized path of the flange (with groove) under the Path1 roadmap: Table 1 Length Membrane Bending Membrane+Bending Peak Total 0. 49.214 323.46 320.19 159.42 479.6 0.12654 309.99 306.87 87.552 394.31 0.25308 296.51 293.57 69.33 362.57 0.37963 283.03 280.29 51.485 331.02 0.50617 269.55 267.03 34.294 299.66 0.63271 256.08 253.79 19.046 268.49 0.75925 242.6 240.58 12.985 240.29 0.8858 229.12 227.39 12.961 222.12 1.0123 215.64 214.25 14.794 203.97 1.1389 202.16 201.15 17.962 185.85 1.2654 188.69 188.1 21.928 167.78 1.392 175.21 175.12 26.367 149.78 1.5185 161.73 162.21 28.014 135. 1.645 148.25 149.41 29.022 121.11 1.7716 134.78 136.74 30.102 107.45 1.8981 121.3 124.24 31.25 94.083 2.0247 107.82 111.97 32.463 81.151 2.1512 94.344 100. 32.897 69.616 2.2778 80.866 88.478 32.102 60.063 2.4043 67.388 77.583 31.344 51.763 2.5308 53.911 67.625 30.631 45.388 2.6574 40.433 59.08 29.971 41.804 2.7839 26.955 52.64 29.373 41.716 2.9105 13.478 49.141 27.611 45.015 3.037 2.9591e-012 49.214 25.873 50.692 3.1636 13.478 52.844 24.188 58.04 3.2901 26.955 59.383 22.575 66.494 3.4166 40.433 67.995 21.058 75.674 3.5432 53.911 77.998 19.179 85.27 3.6697 67.388 88.923 17.041 95.128 3.7963 80.866 100.47 15.033 105.2 3.9228 94.344 112.45 13.228 115.42 4.0493 107.82 124.73 11.736 125.75 4.1759 121.3 137.24 10.549 136.22 4.3024 134.78 149.92 9.1401 147.02 4.429 148.25 162.72 8.4919 157.88 4.5555 161.73 175.63 8.7995 168.78 4.6821 175.21 188.61 9.9968 179.7 4.8086 188.69 201.66 11.835 190.65 4.9351 202.16 214.77 13.454 202.28 5.0617 215.64 227.91 15.396 214.15 5.1882 229.12 241.1 17.736 226.04 5.3148 242.6 254.31 20.354 237.95 5.4413 256.08 267.55 23.169 249.88 5.5679 269.55 280.82 25.963 262.27 5.6944 283.03 294.1 28.715 275.56 5.8209 296.51 307.4 31.76 288.87 5.9475 309.99 320.71 35.038 302.2 6.074 323.46 334.04 38.503 315.55 Equivalent stress on the linearization path of the upper flange: Table 2 Length Membrane Bending Membrane+Bending Peak Total 0. 43.825 270.58 281.34 109.29 386.96 0.12883 259.31 270.2 84.483 352.27 0.25767 248.03 259.08 62.337 319.71 0.3865 236.76 247.97 47.636 294.13 0.51533 225.48 236.88 33.135 268.84 0.64416 214.21 225.8 18.812 243.82 0.773 202.93 214.75 4.7104 219.07 0.90183 191.66 203.71 2.7894 201.41 1.0307 180.39 192.71 8.1413 184.76 1.1595 169.11 181.74 13.72 168.17 1.2883 157.84 170.81 19.318 151.64 1.4172 146.56 159.93 24.211 135.87 1.546 135.29 149.11 25.684 123.56 1.6748 124.02 138.35 27.156 111.31 1.8037 112.74 127.69 28.63 99.165 1.9325 101.47 117.14 30.111 87.131 2.0613 90.193 106.74 30.62 76.236 2.1902 78.919 96.543 29.993 66.721 2.319 67.645 86.607 29.361 57.566 2.4478 56.371 77.04 28.727 48.955 2.5767 45.097 67.999 28.097 41.213 2.7055 33.822 59.722 26.653 35.616 2.8343 22.548 52.572 24.948 32.238 2.9632 11.274 47.065 23.25 31.45 3.092 1.5181e-013 43.825 21.566 33.417 3.2208 11.274 43.363 19.881 37.707 3.3497 22.548 45.764 17.725 43.71 3.4785 33.822 50.621 15.597 50.631 3.6073 45.097 57.314 13.521 58.137 3.7362 56.371 65.28 11.536 66.022 3.865 67.645 74.109 9.6186 74.251 3.9938 78.919 83.53 7.7308 82.815 4.1226 90.193 93.362 6.1995 91.487 4.2515 101.47 103.49 5.3655 100.24 4.3803 112.74 113.83 5.5754 109.04 4.5091 124.02 124.34 6.3589 118.25 4.638 135.29 134.96 7.5674 127.71 4.7668 146.56 145.69 9.1862 137.19 4.8956 157.84 156.49 11.05 146.68 5.0245 169.11 167.36 13.064 156.19 5.1533 180.39 178.27 14.437 166.61 5.2821 191.66 189.23 15.918 177.11 5.411 202.93 200.23 17.536 187.62 5.5398 214.21 211.25 19.267 198.14 5.6686 225.48 222.3 20.886 208.96 5.7975 236.76 233.37 21.953 220.87 5.9263 248.03 244.45 23.247 232.79 6.0551 259.31 255.56 24.741 244.72 Table 3 Stress assessment path stress classification of dangerous flange paths Stress value assessment conclusion Path1 Local film stress 49.214