Etabs 9.7.3 crack code#
Etabs 9.7.3 crack free#

Etabs 9.7.3 crack code#

Even if they could, the unpredictability and uncertainty in the parameters affecting the softening branch of the system performance (dynamic properties of the systems, soil property, hinge property, e.t.c.) still are too high that the code simply prefers to push this point farther to the systems performance level. Nonlinear static algorithms, both force-control, and displacement-control cannot capture such a phenomenon when evaluating the whole structure. At this point, the structure becomes so soft that it can not withstand its own weight and start to deform laterally due to P-Delta forces without any external forces.

During a severe ground excitation, structures may experience dynamic instability, which is the consequence of softening the whole system.

Therefore, the cumulative deformation (inelastic) experienced by a system, which is the primary source of damage, can be significantly more than its maximum one. However, in an actual earthquake, the structure may experience multiple cycles of inelastic deformation, which cause deterioration and degradation both in element and system scales that subsequently diminish the system's capacity.

A nonlinear static analysis, what ASCE 41 calls NSP, is supposed to simulate the performance of structures during real earthquakes.You can quickly come to this conclusion from looking at the assumptions behind calculating the effective period (Te), modification factors (c0, c1, and c2), and see how simple and applicably-limited they are. It only gives an estimate of the experienced displacement by the system during an actual earthquake. As you certainly know, the procedure for calculating the target displacement of the structures is somehow inaccurate.But why? here I try to mention primary explanations for such a regulation briefly: This criterion is to provide enough safety margin between the target performance point and the incipient collapse level of the whole structure. for best understanding i upload my model in opensees and etabs. i try all patterns i found but i can't verify my model because i can't understand how opensees run modal analysis and make eigen values. 'mass moment of inertia about height axis'Įtabs calculate mass moment of inertia with multiple each mass of nodes by distance of node from center of mass then sum these valus and attain mass moment of inertia abuot height axis. Mass n 'mass in x direction' 'mass in y direction' 0. in first condition i assigned mass moment of inertia like that i try both assigning mass to nodes and center of mass.

i found that etabs centeralized all masses in center of mass and then make mass matrix with 3 parameters like thatĠ 0 mass moment of inertia about hight axis ]īut i wondering opensees generate mass matix for each node(also we can use center of mass for assigne mass) and also mass matrix for 6 dof model with 3 limited dofs (dofs limited in z direction and rotation about x ,y axis) is 6*6, so i'm confused to understad how opensees derrive mass matix and calculate modal frequences. in my reaserch i found that mass moment of inertia is principle parameter in model with mass IIrregularity, so i try figure out how modal analysis run in etabs and opensees and what difference between them. i trying almost everythings to verify it but Unfortunately all my work was unsuccsesfull. i builded the model in etabs and can verify my model with 0.33% error, but i couldn't verify model in opensees. i use a model from a reasercher's article, he note that the modal frequences of first three mode is 1.16, 1.96, 2.37 HZ respectively. the model has no beam, so i used rigid diaphragm to equal dof of top nodes of columns. I'm trying to model a 3D one story buiding with mass IIrregularity, the model has 4 elastic columns and rigid diaphragm.

Etabs 9.7.3 crack free#

So, how should i model strut so that it will be tension free and it takes only compression? how can I model it in ETABS so that it will not take any live and dead load from the structure? and i am not quit clear about that should strut is modeled for Nonlinear analysis( Pushover, nonlinear time history ) only OR can it be modeled for Linear dynamic such (RESPONSE SPECTRUM, LINEAR TIME HISTORY ) analysis? and how can i model it in Linear dynamic analysis? And i am not able to make it not to take Dead and live load response,as infill should not take any dead and live load from the structure.

BUT i am unable making it not to take Tension in strut when running the analysis. I have modeled strut assuming pinned jointed frame element having material properties as per masonry property as per Indian Standard. I have to consider infill consideration in the building, So i have calculated Strut width as per FEMA 356, using masonry property of Indian Standard. I am doing Response spectrum and Linear time history analysis in RC building for my project.