Search found 915 matches

by huffte
20 Jun 2021, 22:05
Forum: 02-Analytical capabilities
Topic: record scaling
Replies: 1
Views: 9

Re: record scaling

There are various definitions of scaling parameters in modern design codes and specifications. Some rely upon a geometric mean response spectrum of the two horizontal components. Others rely upon a maximum direction response spectrum of the two components rotated through all possible angles. Yet oth...
by huffte
30 May 2021, 14:51
Forum: 03-Analytical/modelling capabilities
Topic: Big slope in linear part for force-displacement curve
Replies: 8
Views: 5169

Re: Big slope in linear part for force-displacement curve

Hi kaysisig. My advice would be to double-check all settings (geometric non-linearity, convergence criteria, etc.) and to study the verification problems which might be somewhat similar to what you are trying to accomplish with your model. It is not surprising that a change in stiffness modifier did...
by huffte
29 May 2021, 01:54
Forum: 03-Analytical/modelling capabilities
Topic: Big slope in linear part for force-displacement curve
Replies: 8
Views: 5169

Re: Big slope in linear part for force-displacement curve

What type of element are you using? Force-based (infrmFB) or displacement-based (infrmDB) or some other? If the elements are relatively short, you should probably be using DB. If you are using a single, relatively long element for the column, then you should probably use FB. Element type can really ...
by huffte
22 May 2021, 15:58
Forum: 03-Analytical/modelling capabilities
Topic: PUSHOVER ANALYSIS
Replies: 15
Views: 2346

Re: PUSHOVER ANALYSIS

You may set up the appropriate criteria in the Performance Criteria. After the analysis the Performance criteria log in the post-processor will tell you exactly which criteria (plastic hinge) was reached, where it reached, and the load factor at which it was reached, enabling you to track the progre...
by huffte
17 May 2021, 13:57
Forum: 03-Analytical/modelling capabilities
Topic: CFT modelling
Replies: 8
Views: 738

Re: CFT modelling

For bridge structures using CFT, AASHTO specifies an in-ground, analytical plastic hinge length of (0.1H1 + 1.25D), but no greater than 2D. H' is the distance from the ground surface to the point of contraflexure. D is the diameter of the tube. For acceptance criteria, the compressive strain in the ...
by huffte
14 May 2021, 13:55
Forum: 03-Analytical/modelling capabilities
Topic: CFT modelling
Replies: 8
Views: 738

Re: CFT modelling

Could you not use the 'css' section and remove all longitudinal reinforcement? And you could set the transverse hoops to something extreme (say, 2mm bars spaced at 2 meters) to effectively eliminate their influence. It seems you could further reduce the influence of any reinforcement by specifying t...
by huffte
13 May 2021, 19:44
Forum: 02-Getting started with the modelling
Topic: How to add a sequence cyclic load (force then displacement Cycles) and obtain hysteresis curves ?
Replies: 6
Views: 1195

Re: How to add a sequence cyclic load (force then displacement Cycles) and obtain hysteresis curves ?

You might try the Verification Report and associated SeismoStruct files. In particular, Chapter 4, Example 3 may be helpful. There are others which may suit your needs as well. The SeismoStruct YouTube videos may help too, though I am not sure if there is anything specific to cyclic pushover as I ha...
by huffte
13 May 2021, 00:57
Forum: 03-Analytical/modelling capabilities
Topic: Increasing Ductility Demand
Replies: 3
Views: 582

Re: Increasing Ductility Demand

I think the most important concept will be to be explicit in reporting your results regarding how you established the yield displacement. I would say that a large number of studies have historically relied upon the idealized value. But, as I say, just be precise and specific about the results you re...
by huffte
11 May 2021, 23:23
Forum: 03-Unexpected behaviour/errors
Topic: Period elongation on Response spectra
Replies: 3
Views: 827

Re: Period elongation on Response spectra

I confess to being a bit confused on your question. Are you saying that the original time history matches the target closely to start with? Then why is spectral matching required? Certainly, spectral matching would not result in a lesser match to the target. What do you mean when you say you have "a...
by huffte
11 May 2021, 23:15
Forum: 03-Analytical/modelling capabilities
Topic: Increasing Ductility Demand
Replies: 3
Views: 582

Re: Increasing Ductility Demand

If the first floor columns hinge prior to any beam hinges, it would seem that the first floor columns are under-designed. You can examine hysteresis curves for beams in the post-processor to see if, indeed, they remain elastic for the entire pushover analysis. Regarding whether to use first yield or...

Go to advanced search