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Hi Sean
Lecture 5@3:30: why there are only 2 reactions at those 2 corners? (instead of 4 reactions at 4 corners?)
Hey Tien - no good reason! We could/should draw reactions at 4 corners.
S
@Tien @Sean Hi Tien and Sean, as far as i understood, what tien mean why do not we have horizontal reactions on supports ? @Sean please correct me if i am wrong:
Because external force is applied lets say in -z direction lets say, we can only have a reaction in supports in +z direction by statics, right? (Considering our cross section is a plate as we see here.
However, in shells case it is not the case, we will have horizontal components in support reactions due to curved nature of a shell, horizontal internal forces are generated even in the presence of -z direction external force only (think like a arch case in 2D, when we apply -z direction external force due to curved shape of our system (arch) we automatically have horizontal component in our supports because normal force carried on our arch system is decomposing itself in support nodes in x and y direction due to angle of curvature, which ends up in Reactions in x and Reactions in z direction lets say) , i believe that is the main difference of plate and shell due to their initial/system curvature support reactions even change direction wise and magnitude wise.
Regards,
Burak