พอดีสงสัยเรื่องหา Stiffness Modifier ใน SAP2000 และ ETABS ครับ
Assuming beams and columns are modeled as frame then the stiffness modifier table is as follows:
ACI ETABS
Beams........................................0.35*Ig I22 = I33 = 0.35
Columns....................................0.70*Ig I22 = I33 = 0.70
Walls-Uncracked.................0.70*Ig modeled as shell – f11, f22 = 0.70
Walls-Cracked......................0.35*Ig similar to Walls-Uncracked (with modifiers of 0.35)
NOTE:
Walls are generally not designed for out-of-plane bending to avoid excessive longitudinal reinforcement. In this case, use a small modifier say 0.1 for m11, m22 and m12 so numerical instabilities could be avoided. However, use m11, m22, m12 = 0.70 (or 0.35) when considering the out-of-plane bending in wall.
Flat Plates & Flat Slabs....0.25*Ig modeled as membrane – f11, f22, f12 = 0.25 / modeled as shell – f11, f22, f12, m11, m22, m12 = 0.25 (for both cases fxx is not important if rigid diaphragm is assigned)
พอดีไปเจอบทความจากเวปนี้มา
https://wiki.csiamerica.com/display/etabs/Modeling+concrete+cracked+section+properties+for+building+analysis
อยากทราบว่าจำเป็นต้องใส่ตอน model โครงสร้างด้วยหรือป่าวครับ
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ค่า Stiffness Modifier ใน Sap2000 และ Etabs
Assuming beams and columns are modeled as frame then the stiffness modifier table is as follows:
ACI ETABS
Beams........................................0.35*Ig I22 = I33 = 0.35
Columns....................................0.70*Ig I22 = I33 = 0.70
Walls-Uncracked.................0.70*Ig modeled as shell – f11, f22 = 0.70
Walls-Cracked......................0.35*Ig similar to Walls-Uncracked (with modifiers of 0.35)
NOTE:
Walls are generally not designed for out-of-plane bending to avoid excessive longitudinal reinforcement. In this case, use a small modifier say 0.1 for m11, m22 and m12 so numerical instabilities could be avoided. However, use m11, m22, m12 = 0.70 (or 0.35) when considering the out-of-plane bending in wall.
Flat Plates & Flat Slabs....0.25*Ig modeled as membrane – f11, f22, f12 = 0.25 / modeled as shell – f11, f22, f12, m11, m22, m12 = 0.25 (for both cases fxx is not important if rigid diaphragm is assigned)
พอดีไปเจอบทความจากเวปนี้มา https://wiki.csiamerica.com/display/etabs/Modeling+concrete+cracked+section+properties+for+building+analysis
อยากทราบว่าจำเป็นต้องใส่ตอน model โครงสร้างด้วยหรือป่าวครับ
ฝากผู้รู้ช่วยตอบที่ครับ