11-03-2010, 05:24 AM
@ Veggeta, I agree with you. I just needed to know as per which code of practice your spreadsheet was prepared.
You will believe me that this method(used in the spreadsheet) is not just out of simple statics but a codal requirement.
I am not against it(of course it holds for its code provisions) but just want us to share some of its draw backs in regards to calculation of the width of the strut. Its similar to the New Zealand code requirement.
1) Calculation of the width, w of the strut is an ex- ETABS or ex-SAP piece of work.
2) ETABS will need, correct me if i am wrong, w,t, Em for calculation of the stiffness of the strut( what would be an equivalent of the stiffness of masonry).
3) The New Zealand code estimates w=D/4 ( just an empirical value). D is the length of the diagonal strut.
4) As per Hendry (1998), w=f(Ef,Em,Ic,Ib,t,h,L,@)
where Ef=Youngs modulus of frame material
Em=Youngs modulus of masonry
w= width of strut
Ic=moment of inertia of column
Ib= moment of inertia of beam
h= height of masonry
L = length of masonry
@=angle of inclination of strut
5) Holmes (1963) estimates w=D/3
If you try to calculate w using any of the above methods, Hendry comes out to be more economical than the rest ( it takes a lot of factors into considerations).
ETABS/SAP will take the w we give them so if its conservative, results will be definitely conservative because w will affect the stiffness of the strut.
@ Veggeta, please try mentioning the code for which your spreadsheet is based. This will refrain us from conflicting code requirements.
Regards.
You will believe me that this method(used in the spreadsheet) is not just out of simple statics but a codal requirement.
I am not against it(of course it holds for its code provisions) but just want us to share some of its draw backs in regards to calculation of the width of the strut. Its similar to the New Zealand code requirement.
1) Calculation of the width, w of the strut is an ex- ETABS or ex-SAP piece of work.
2) ETABS will need, correct me if i am wrong, w,t, Em for calculation of the stiffness of the strut( what would be an equivalent of the stiffness of masonry).
3) The New Zealand code estimates w=D/4 ( just an empirical value). D is the length of the diagonal strut.
4) As per Hendry (1998), w=f(Ef,Em,Ic,Ib,t,h,L,@)
where Ef=Youngs modulus of frame material
Em=Youngs modulus of masonry
w= width of strut
Ic=moment of inertia of column
Ib= moment of inertia of beam
h= height of masonry
L = length of masonry
@=angle of inclination of strut
5) Holmes (1963) estimates w=D/3
If you try to calculate w using any of the above methods, Hendry comes out to be more economical than the rest ( it takes a lot of factors into considerations).
ETABS/SAP will take the w we give them so if its conservative, results will be definitely conservative because w will affect the stiffness of the strut.
@ Veggeta, please try mentioning the code for which your spreadsheet is based. This will refrain us from conflicting code requirements.
Regards.