MC 10	Eurocode 2
Limit of the section wall thickness	Wall thickness of the hollow section: $t=t_{real}$ Wall thickness of the plain section (equivalent hollow section): $t=$2x distance between the face of the section and the axis of the longitudinal reinforcement and $t\le x/8$.	Wall thickness of the hollow section: If $t=A/u\le t_{real}$ the section is considered as a hollow section; If $t=A/u>t_{real}$ the section is considered as a plain section (equivalent hollow section).Wall thickness of the plain section (equivalent hollow section): $t=A/u$ e $t>$ 2x distance between the face of the section and the axis of the longitudinal reinforcement.
Shear stresses and shear forces due to torsion	Shear stress at a wall $i$: $V_i=\frac{T{z}_i}{2A_k}$	Shear flow at a wall $i$: ${\tau }_i{t}_i=\frac{T}{2A_k}$ Shear stress at a wall $i$: $V_i={\tau }_i{t}_i{z}_i$
Safety condition	Condition:  $V_R=V_{Rc}+V_{Rt}\le V_{R,max}$ Approximation level II:  $V_{Rc}=0$  $V_{Rt}=\frac{A_t}{s}{u}_k{f}_{yt}\cot \theta$	Condition: $\frac{T}{T_{R,max}}\le 1.0$  $V_R=\frac{A_t}{s}{u}_k{f}_{yt}\cot \theta$
Maximum limit by the tension in concrete struts	Maximum limit: $V_{R,max}=k_c\left(\frac{f_{ck}}{{\gamma }_c}\right)t{u}_k\left(\frac{\cot \theta -\cot \alpha }{1+{\cot }^2\theta }\right)$ Approximation level II: $k_c=0.55{\left(30/f_{ck}\right)}^{1/3}\le 0.55$ and $\alpha =90º$	Maximum limit: $T_{R,max}=2\nu {\alpha }_{cw}{f}_c{A}_{k}t\sin \theta \cos \theta$ where $\nu =0.6\left[1-\left(f_{ck}/250\right)\right]$ and ${\alpha }_{cw}=1$, for non-prestressed beams.
*	${\cot }^2\theta =\frac{2A_l{f}_{yl}s}{A_t{f}_{yt}{u}_k}$	${\cot }^2\theta =\frac{A_l{f}_{yl}s}{A_t{f}_{yt}{u}_k}$
* Angle between the concrete struts and the longitudinal axis of the beams.