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_sY37F0CqnlxyP-ODHdcf9zhwgnlePm8_RzmNoPZGp_SddF6jsUhpO0APTY8SSHgvc5G9keFQvF_uPNzRtLsBQ8wXcQG7PMJ8s32_3l7zAbetg2icjkg1mk_EnH2HoCSIjJ0xTcBjmwH3PFtEw8ax-d2c31D4x19RlBAIRpTxGsxhSEBHqDtvrhtMN5JY5Co8NGDPtdNhjHTDVuTemduQg6oDq_9whwUy9MXanMWQtDqfl6cRRmZGowwWFEwU8Lk2olfAwrc9a0A7UTqFxX5KAJLt1o=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_uVYhbNCqEPOhcFgzEAmTcUq7CZMVfQEQ0Cph6_V1-ITle1pJV9HW7Tcto7AMED1yODN4XxjpYFComkFiXROwPXyVWEFQ3cBfJCI9GovOD8k1EBLjbua61_aGwawTII2VoKZBwK7eoJJXxjyZqyeuaU7R0SAscO78QHXDf2SDEXfF_AZqStLAFP43MJumf_GM8X3ojiqc0e0Biqt9L28j31oGPMqRMmlB5Mdv1mtH6-xawmzhQGcRhbYpJpLoVCR6W_dhEiEWfNAP5h-Quia4kpUr6oXt3Cg4GGy5lEX4Tt8o8oUyORVDG4lNs7ljr7r5EvGxPb6G9ARcRdIehqnWLHt28LIVMGsB1OSLcZRwgyAEpU0CWLfkirawV-b4KZ24uAu9DfF92_FmZbRSYD_z7U7n_fk9zuk9VBLObTxuyf4sI1uuI7XR9lNccO01frAs5E=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_vGt8kQ9HUuaNYFxsBYf-AfrvZfMR_GGmiWaEEkJB443ZaY493UvcerpMTlkAFP7rSaK6fnPIj9UPxvAjJX52OR99l359NkLat6UCwi6i3v67FO7QkeQivrtWK-hMJRahtBnO1nlbHrSAI9vJjXoV06SVsxtPV4135EomWisffwpTYv-Ubb2DfSLrt5ci1FrXXJOoXTyP8MDHTscLW6-JIZnWp0wosLy1qQ7oSeIpQ8Q3-b8Qitc2dceWkqWryrEupWFRd_pEvnz0xK23Zo1VoMm9_yuf8elonjf9rqOy1n6hPQiVQG0HnJWpmpQqQY-J1VVuHpQrL8xsEJkLlQjF7KbBYrTYId8WVGa092olctL9A8w4SadqZS8VJubf2XB4_RWXUW3YW1P2S0jsg467g4y0C2hP3AqLMhBn4qp8-aLr-rcHNir6A=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。