I work for the same problem recently, and I choose the Chapter 11 of Taiwanese LSD Code to solve the yield problem. I can calculate the limitation of the flange or web for the H beam, and the formulas are just to control its allowable reaction force. Of course, the reaction force may be too large for the H beam, but I can choose the larger H beam for the engineering construction design. The ASTM A572 Gr.50 H beam, RH900x300x16x28, is selected, and the formulas 11.2-1 & 11.2-2 are also selected for the present situations. If you wanna know how to define N, you can see the Figure C11.2-1 where is located on the Taiwanese LSD Code. Besides, the parameter k is NOT tf, but you have to include the circular region which is k = tf + R. In my engineering case, I don't have to add the stiffening plates, so that I just provide the fundamental formulas. The steel material is not JIS or CNS standard, so that I don't have to reduce the yield stress Fyf for the flange whose thickness is less than 1.5in. Hence, I can check whether the size of H beam is enough or not, so that the yield problem has been solved.



![=1.0\times \left [ 5\times \left ( 2.8+1.8 \right )+40 \right ]\times 3.52\times 1.6=354.816tf>R_{u}=82.392tf](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_vQvW99_WInGyCg3K0ulChaE-XXWk0FaMfxjVdQpuRmvHgbtTsyuNCPLwdWL4Y7FQFobo6LWG4j_WvpakAzNNUVWNAGKxxaEk5nQPBfWxL_Ftsas5lyqbhEjah6kA54Sj-bePPBILdyUz6b2uMmDF7hkuKUI06FzD479vmzQC8zuclKrmds1dEGTUdG5PhHm1B8B89QFc54k3Wu6lMtr7KDaZlpbkbTLdGu29LYfRZ98b8fx_HjKYHnIXwDGKxpBRqrimZUZ3Su769QzWertEjf0lbB=s0-d)
![\phi R_{n}=0.75\times 36t_{w}^{2}\left \{ 1+3\left [ \frac{N}{d} \right ]\left [ \frac{t_{w}}{t_{f}} \right ]^{1.5} \right \}\sqrt{\frac{F_{yw}t_{f}}{t_{w}}}](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_u7CZseUFCnkC4uwqdUla9TkTA1c-dEdK_R4RC6L1S-br3SzWyg_0xi0mib5lqjyHnYhd4lvPOlB__A2D1NjGLlkaJCtzZnxpLMibMpmACWKAf_IujVn_8_-gc5oUnKCp3xDyG9Djc78fZvmvAOOSgXaV2vzGFhmI_I5RGKdhn-wc8UZ7WcUJ_6_xRAiDdFyMUwmUYhXTimy-bX_kOrMG_1uq2teZDklAZWCrj9LMC9CT4N74QexgXrDSFBDm-aF3ITLHHbIg5KqQFMKAweXisg6U9CewFtBJq-Ae-6-uquUHZ8O_2VQv9Pl7-UysdLvp0nUwbYrop8d9vhmmRgyIfygER44RILlTeOn06EShJQdzB-Q6AiZVg-LmMWILG6OAxK7oOWkg8lw0dgfh13ht-1pGNAQpemCl51iGzjZ2PjHp1l1nJd2nyqBRJadqPSjJVi=s0-d)
![=0.75\times 36\times 1.6^{2}\times \left [ 1+3\times \left ( \frac{40}{90} \right )\times \left ( \frac{1.6}{2.8} \right )^{1.5} \right ]\times \sqrt{\frac{3.52\times 2.8}{1.6}}](https://lh3.googleusercontent.com/blogger_img_proxy/AEn0k_tG3Uvhb732e6xwi5q9OhVtphhLdj84lFwhYEQZCPFaaKVgZDDKh0keBw6gCG865PUDn3kgSy7RbbAPgfrNuXrlgwLBl57zH6fE2T3qKBcblSo4zYzhm4lUNiWjmSiurKaZ64i0GUJEDEP1-yLdfleSsWn5-9WJmuokF2wKFsFqR2qxv5UHNKCHE29V9P4y7wBKsw6QO3d30Olxd3s-yKwGn5pwtZ17tQTHc1v3pSUnAdvDQqOqaW5NFx6qMfsER3ldiOxYNCNdDIJS7L94YOstwUBfkqAF3kAHwQbAf671JtjwT8-UWWOfsVl2N0QcH4P0pz4lGlQ3exmk22Muwzau2HuxCgH3D1vTSaCJPR8gkAaFzQJCgRk_XLuu9KFdcITldkMgMm5sBOwka9Yj8wSEcNA5uG8LQgV7ORh-0Foa-gSOqp8UC1A=s0-d)

Reference
Reference
- 內政部營建署(2010)鋼結構極限設計法規範及解說,內政部營建署。