Hello @MR_11012943
Thank you for sharing the screenshot of the error within your Mathcad worksheet. The convergence issue seems to be arising in the section where root-finding functions root and on error are used. These types of numerical methods can be quite sensitive, and several factors could be contributing to the non-convergence.
The initial estimate 'ztrial' appears to be set at 1 mm. If the actual root is far from this estimate, or if the function's behavior is complex near this guess, the root finder might fail. Consider choosing an initial guess closer to the expected root based on the physical context of your problem.
Examine the functions N_total, e_conc_crush, etc., to ensure they are continuous and well-behaved (i.e., no discontinuities or steep gradients) around the initial guess and the expected root. Discontinuities and rapid changes can cause difficulties for the root-finding algorithm.
