The py_RC Elastic spreadsheet (last discussed here) has been updated with a new function py_Biax, providing elastic analysis of reinforced concrete sections under combined axial load and biaxial bending. The new spreadsheet and associated Python code can be downloaded from:
The download file includes full open-source Python code. For details of the pyxll package required to link the Python code to Excel see: https://newtonexcelbach.com/python-and-pyxll/
The code and spreadsheet layout are based on the VBA version presented at: Elastic Biaxial Bending
Input for a T-section beam is shown in the screenshot below. The concrete is defined by the coordinates of each corner point, and reinforcement is is detailed in layers, with the coordinates of the ends of each layer:
The angle of the neutral axis is found by iteration, and the estimated angle should be entered in cell E5, then click the “Adjust NA Angle” button. The NA angle and position will be adjusted so that the stress at both ends of the NA is zero:
The function output displays:
Concrete, reinforcement and combined section properties:
Concrete stresses at each corner of the section in compression:
Reinforcement stresses at the ends of each layer:
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