Validation & Verification of automated non- linear ... · aethereng.com Validation & Verification...
Transcript of Validation & Verification of automated non- linear ... · aethereng.com Validation & Verification...
aethereng . com
Validation & Verification of automated non-linear modelling for the seismic response of
cross laminated timber structures
Lorenzo Riparbelli
Ioannis P. Christovasilis
- Par i s , 20 .03 .2018 -
aethereng . com
The Big Picture The Professional use
ImportCAD Geom.
Create ModelGeometry and Mesh
Perform Linear Analyses
To determine sections,To design for regulatory codes
Perform NON-LINEAR analyses.
OptimizationPerformance-based DesignResilience-based Design
All with AUTOMATED Procedures
aethereng . com
Our Strange Friend:Wood
▪ Composite layout
▪ Different bending stiffness in the two maindirections and planar stability
▪ Use both as walls and floors
CLT Panel
Anisotropy
aethereng . com
Global Behaviour dominated byContact and Discrete Connections
Seismic BehaviourRocking (rotation) and Sliding for each panel
Monolateral contact
Tension-onlyhold-down
Shear-only discrete + Friction
aethereng . com
Global Non-linear BehaviourConnectors:o No Resistance in compressiono Pinching Response in tension/shearPanels:o Monolateral contact
Uplift
Link Video: https://www.dropbox.com/s/7y6nez1yewim94d/Deformed_C4-Kobe-082.mp4?dl=0
aethereng . com
Modelling Approach
aethereng . com
Modelling Approach
Wall Face Wall-to-Wall Contact Face
Wall-to-Floor Contact Face
Floor Face
aethereng . com
Modelling Approach
Wall Assembly
Floor Assembly
Wall Assembly
Wall Assembly
Wall Assembly
Coincident nodes
1st generation model
2nd generation model
▪ LIASON GROUP on DX, DY, DZ
▪ Contact face material properties
based on connections
▪ Contact Zones
▪ Formulation CONTINUOUS
aethereng . com
AB
AB
Angle Bracket (AB)
K_T_D_L springs with shear stiffness
Connections
aethereng . com
WFC
Connections
WC / WFC / FCK_T_D_L springs with axial and shear stiffness
WC
WC
aethereng . com
HD
Connections
Hold-down (HD)K_T_D_L springs
with axial stiffness
HD
aethereng . com
Connections
Static non-linear analysis
▪ K_T_D_L spring with axial stiffness and
kinematic hardening (DIS_ECRO_CINE)
▪ CABLE element
Dynamic non-linear analysis
▪ K_T_D_L spring with axial stiffness and
kinematic hardening (DIS_ECRO_CINE)
▪ K_T_D_L spring with axial stiffness and
asymmetric hardening (ECRO_ASYM_LINE)
HD as two elements in series
aethereng . com
Sofie Project Real Scale Test on CLT Structure
CNR-IVALSA(Italian National Research Council – Trees and Timber Institute)
Scientific Director: Prof. Ing. Ario Ceccotti
Funded by: Provincia Autonomadi Trento
In collaboration with:
aethereng . com
The model
o 449 faces (61 CLT panels)
o 204 common edges with contact&friction
o 1543 discrete elements, thatrepresent 9 different types of connectors
o Panels are connected with 211 different connections
aethereng . com
The model
All groups and contact zonescreated automatically
aethereng . com
Validation Process
o Linear Elastic Model
o Non-linear with contact without friction
o Non-linear with contact and friction =0.2
o Non-linear with contact and friction =0.4
Subjected to
o Kobe JMA motion scaled to 0.15g
o Cyclic Pushover analysis
Validation based on:
o Hysteresis loops
o Time-history of base shear and drift
o Vibration periods
aethereng . com
Linear model
modeltest
+16.8
+34.7
+115.7
+98.0
aethereng . com
Non-linear modelContact without friction | µ = 0.0
modeltest
+13.3
+40.2
+139.0
+130.5
aethereng . com
modeltest
-4.7
-2.0
+37.2
+17.3
Non-linear modelContact with friction | µ = 0.2
aethereng . com
modeltest
-0.6
+3.3
+24.7
+9.3
Non-linear modelContact with friction | µ = 0.4
aethereng . com
Phenomenological Difference for low acceleration
With LiasonsNo-Separation
With Contact &Friction
aethereng . com
Comparison
model-µ=0.0test
model-µ=0.4linear model
modelµ=0.0
modelµ=0.2
modelµ=0.4
Max Shear
+16.8% +13.3% -4.7% -0.6%
Min Shear
+34.7% +40.2% -2.0% +3.3%
Max Drift
+115.7% +139.0% +37.2% +24.7%
Min Drift
+98.0% +130.5% +17.3% +9.3%
aethereng . com
Comparison
model-µ=0.0linear model
model-µ=0.4
0.40F
0.48F
0.12F
0.45M
0.45M
0.10M
aethereng . com
Comparison
model-µ=0.0linear model
model-µ=0.4
Link Video: https://www.dropbox.com/s/bvjdi3hmn5j6t1q/Cyclic_C7_High.mp4?dl=0
aethereng . com
Comparison
0.40F
0.48F
0.12F
0.45M
0.45M
0.10Mlinear model
modelµ=0.0
modelµ=0.2
modelµ=0.4
K1[kN/mm]
86.5 84.0 116.0 120.0
K2[kN/mm]
42.9 39.5 56.4 59.4
K3[kN/mm]
15.2 14.1 20.5 22.0
K1
K2
K3
T1 model[sec]
0.2080.213
0.214 0.180 0.176
T1 test[sec]
0.183 0.183 0.183 0.183
Perc. Diff. +13.7%+16.4%
+16.9% -1.6% -3.8%
And for Professional Application??
aethereng . com
Fields of Verification
1. Combined axial (compression or tension) and moment-induced stresses in the longitudinal direction of the panel (grain direction of external layer);
2. Shear stresses for perpendicular-to-plane shear forces in the longitudinal direction of the panel (grain direction of external layer);
3. Combined axial (compression or tension) and moment-induced stresses in the transverse direction of the panel (perpendicular-to-grain direction of external layer);
4. Shear stresses for perpendicular-to-plane shear forces in the transverse direction of the panel (perpendicular-to-grain direction of external layer);
5. In-plane shear stresses as maximum between gross, net and torsional shear.
aethereng . com
Evolutionary Field of Verification (Transient)
Link Video: https://www.dropbox.com/s/7y6nez1yewim94d/Deformed_C4-Kobe-082.mp4?dl=0
Link Video: https://www.dropbox.com/s/bnwcd9tfkxqq5g1/Trans_C4-Kobe-082.mp4?dl=0
aethereng . com
Evolutionary Field of Verification (Cumulative)
Link Video: https://www.dropbox.com/s/n6k9e1row5m517c/Cumul_C4-Kobe-082.mp4?dl=0
Link Video: https://www.dropbox.com/s/7y6nez1yewim94d/Deformed_C4-Kobe-082.mp4?dl=0
aethereng . com
Conclusions
o Automated Structural Modelling for designing complex structures, usingcontact and friction, is indeed possible, thanks to the extraordinarycapabilities of code_aster
o Results of these non-linear analyses are better than linear also for accelerations assimilable to Serviceability Limit States, given the factthat the dynamic characteristics of the structure vary also for low accellerations
o These modelling methodologies can be extended to other structuralsystems (for structures where the performance or resilience is relevant)
Thank You!!