STIFFNESS MODIFIER/CRACKED SECTION ANALYSIS EXPLAINED IN ETABS

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  • Опубліковано 23 гру 2024

КОМЕНТАРІ • 88

  • @Decodebd
    @Decodebd  5 років тому +17

    The great persons who are disliking my tutorials, I welcome them to comment the reason for their dislike. If there's no reason, only for jealousy you are giving dislike, I will suggest you to ignore my channel & tutorials please. Don't under rate (dislike) any video if you are from a good family.

    • @mdshahebaz9567
      @mdshahebaz9567 5 років тому

      U r right sir

    • @u_tsf
      @u_tsf 5 років тому +2

      yes it's difficult to understand why they dislike without giving the proper reason in comment section .while comment section is open.

  • @noahpangpang
    @noahpangpang 4 роки тому +4

    First of all, thank you for all the great videos. They have really helped me a lot.
    I wanted to clear one thing. In your 10 story building design tutorial, you have provided member beam stiffness modifier of column as 0.7 and beam as 0.35 and 1 as torsional constant. But in frame stiffness modifier ahead, you have provided torsional constant of 0.001 in frame stiffness modifier as well as beam modifier of 0.35 and column of 0.7. However in this video, you have changed torsional constant value to 0.7 in member stiffness modifier. I hope you can clarify my confusion if we need to provide modifer in both frame and member stiffneses or not?

    • @Decodebd
      @Decodebd  4 роки тому +2

      Torsional constant can be provided as 0.001 if beam fails in excessive shear or torsion.

    • @EstructuraMX
      @EstructuraMX 4 роки тому +1

      @@Decodebd i have seen your video on reducing the torsional constant. But is it safe to do it? because some beams fail and when you reduce torsion the are ok, so yo CAN reduce torsion only on interior girders but not edge beams?

    • @jmau065
      @jmau065 3 роки тому

      @@EstructuraMX It is safe to do it as long as you can guarantee "structural redundancy" of your beams, i.e. you have an edge primary beam that is connected to several secondary beams or the slab itself could take the torsional load. It's all a matter on how you can redistribute torsional demand to flexural demand to other members within the structure. An usual value used for torsional constant is 0.10 to 0.05

  • @LWMiraz
    @LWMiraz 2 роки тому +1

    I appreciate the information.

  • @Hanns_designs
    @Hanns_designs 2 місяці тому

    For serviceability checks should we use crack or uncracked section?

  • @josschannel4039
    @josschannel4039 4 місяці тому

    Am using bs code what is the sm factor for beams column and slab

  • @khalidimtiaz4627
    @khalidimtiaz4627 5 років тому +1

    Very well explained Sir. Thanks a lot.

  • @thanmayivishwanath2591
    @thanmayivishwanath2591 Рік тому

    Acc to ACI, torsional constant it is considered as 0.35 and 0.7 for beam and column respectively. Why?

  • @mushasm007
    @mushasm007 5 років тому +1

    Could u please elaborate on etabs modeling consideration n design for bi-axial voided RCC slab

  • @S.A.R.Y.
    @S.A.R.Y. Рік тому

    How to check Global displacement of building at Top level?

  • @dagnadessie751
    @dagnadessie751 Рік тому

    that is nice sight pls keep it up, but i have one question if we assume EQ which load combination we prefer for determining section and reinforcement needed for structural members? 10Q for your support!

  • @mudherabbas4046
    @mudherabbas4046 8 місяців тому

    Very informative...

  • @ayazdin8582
    @ayazdin8582 3 роки тому

    Very well defined with demo

  • @CaballeroNocturno29
    @CaballeroNocturno29 5 років тому +1

    Nice and useful video. Theres is a chance than you provide us the presentation?

  • @himalnepal9780
    @himalnepal9780 4 роки тому

    Thank you for the information. So, we should not analyse/design any buildings using the normal stiffness modifiers( all sm=1)?

  • @challengemyselffrom100toab2
    @challengemyselffrom100toab2 5 років тому +1

    Can i get that slide?

  • @DINESHMaharjan-pe8mt
    @DINESHMaharjan-pe8mt 4 роки тому

    What says in IS 456 code about stiffness modifications?

  • @gowthamsiva3611
    @gowthamsiva3611 3 роки тому

    how to apply modifiers in walls, in memberane or bending?

  • @vasubhadania
    @vasubhadania 3 місяці тому

    How can we use this aspect in Tekla

  • @KyTaPb
    @KyTaPb 5 років тому +2

    I have tried to find this kind recommendations for stiffness reduction in Eurocode or Model Code and could find only in chapter that is related to earthquakes. Have You met these requirements/recommandations in other structural codes except ACI? Are these recommendations only for seismically prone areas?

  • @sachindeshmukh3228
    @sachindeshmukh3228 3 роки тому

    Great video👌💐

  • @sagurkhan5795
    @sagurkhan5795 5 років тому

    Assalamoalikum sir... thanks a bunch for shearing new things ... May Allah Grant you Bless

    • @Decodebd
      @Decodebd  5 років тому

      W.Salam. Wc. Ameen. Jajak Allah.

  • @kal18990
    @kal18990 3 роки тому

    brother can you attach three etab model mention in tutorial

  • @arnelsinconiegue3210
    @arnelsinconiegue3210 5 років тому

    How would you know or how to determine the member that needs stiffness modifies, how to determine if we need to modify its tension, axial or moment etc.

    • @Decodebd
      @Decodebd  5 років тому

      According to code we need to consider structural members as cracked section, as they will have some cracks under loading after certain period. For considering cracked sections we need to assign stiffness modifiers. If you watch the full video with patience you will know when to use stiffness modifiers for service & ultimate condition.

  • @faribasalimi9397
    @faribasalimi9397 5 років тому

    Could you please explain why wall stiffness modifier (f11=1.0) while (f22=f12=m11=m22=m12=0.7)?why f11 stiffness modifier is different from others?By the way, I really appreciate the informative video.It helped me a lot to have a better understanding of stiffness modifiers.

    • @alexminhnguyen2016
      @alexminhnguyen2016 5 років тому

      for wall, or vertical element, local axis 1 is by default, horizontal direction, local axis 2 is vertical direction and local axis 3 is perpendicular to wall face. Open CSI manual you can find the stress direction for each of their element. Here is an example link: wiki.csiamerica.com/display/etabs/Modeling+concrete+cracked+section+properties+for+building+analysis
      f11 = horizontal in plane stiffness, which will define shear stress (mostly). f22 = vertical in plane stiffness, affect directly to axial stress or wall in plane bending stiffness. f12 = diagonal in plane stiffness. Per ACI or EC cracked wall is 0.35, uncracked wall is 0.7
      m11, m22, m12 is out of plan bending or out of plan twisting stiffness, which is not used for shear wall, so we can set these guy back to 0.25, or even as extreme as 0.1.

    • @thanmayivishwanath2591
      @thanmayivishwanath2591 Рік тому

      @@alexminhnguyen2016 Acc to ACI, torsional constant it is considered as 0.35 and 0.7 for beam and column respectively. Whereas others have taken it as 1, why? can you please clarify this

    • @thanmayivishwanath2591
      @thanmayivishwanath2591 Рік тому

      @@alexminhnguyen2016 And Cracked section accoriding to IS 16700 for walls is 0.7, but acc to ACI it is 0.35. Which is correct?

  • @faisaldilshad5373
    @faisaldilshad5373 5 років тому

    Dear Sir,
    Thank you for this video, just want to ask that torsional constant J is 0.35 for beams but for compatibility torsion can we reduce the value up to 0.001 from 0.35 and if we do that the other values of I (moment of inertia) will remain same for beam i.e. 0.35. Kindly explain.
    Secondly we provided stiffness modifiers to account for material non linearity which reduced the stiffness. How we will account for geometric nonlinearity which also reduces stiffness.
    Thanks

  • @jijmr2013
    @jijmr2013 5 років тому +1

    Mr.BD,do you apply the stiffness modifications when you are checking the deflection?

    • @jaimeriofrio1174
      @jaimeriofrio1174 4 роки тому

      @jijmr2013 I have same question with deflection in beams ACI 318-19 cap 24: Table 24.2.2. Maybe, Did you find the answer? Thanks

  • @MustafaAhmed-mb7hu
    @MustafaAhmed-mb7hu 5 років тому

    What will be the moment capacities of cracked members???
    Will this be reduced significantly???

  • @nhandoan7863
    @nhandoan7863 5 років тому

    Dear sir, I saw you reduce the F22 for Wall.
    In guidline of CSI F22 corresponding to EA (axial stiffness) so i think arrord to ACI318, Axial stiffness no need to modify
    Am i wrong? can you explain to me with more detail? Thank you so much.

  • @faribasalimi9397
    @faribasalimi9397 5 років тому

    Hi,I am wondering why in the video the slab stiffness were not modified.Thanks in advance for the response.

    • @Decodebd
      @Decodebd  5 років тому

      This is just comparison for beams & columns. Check recent course in building design we changed stiffness for slab also.

  • @EzekielMariita
    @EzekielMariita 5 років тому +1

    Hi good and informative video. What app do you use to record the screen?

  • @darwisricharlim319
    @darwisricharlim319 5 років тому

    Thank you sir, keep sharing

  • @civilEngineering1145
    @civilEngineering1145 5 років тому

    Should we do reducing the stiffness for seismic analysis?

    • @Decodebd
      @Decodebd  5 років тому

      Yes for 2 different purpose 2 different chart (Service Condition, Ultimate Condition).

    • @civilEngineering1145
      @civilEngineering1145 5 років тому

      @@Decodebd thanks dear,i mean to do the stiffness for the both seismic and non seismic condition should?

  •  5 років тому

    thanks for this helpful video. How can you find source of the (f11,f22,f12,m11,m22) on the table minute 10.16

    • @Decodebd
      @Decodebd  5 років тому

      From CSI knowledge article.

  • @maluandpartners
    @maluandpartners 3 роки тому

    Can you start replying to other comments in the video? I can see in all your videos you reply only to comments which says good video or informative video.

  • @mdshahebaz9567
    @mdshahebaz9567 5 років тому

    And sir what about indian code.

  • @khanthavel6574
    @khanthavel6574 5 років тому

    Very useful sir
    Thank you.

  • @ramiibrahim7488
    @ramiibrahim7488 5 років тому

    great job , go on

  • @waruthp
    @waruthp 5 років тому

    Thank you for sharing

  • @harfianashari2704
    @harfianashari2704 4 роки тому

    can you add english subtitle for this video

    • @Decodebd
      @Decodebd  4 роки тому +2

      The video is already in English

    • @harfianashari2704
      @harfianashari2704 4 роки тому

      @@Decodebd but for someone who arent good at listening english language it become a problem. So if you have time please make the subtitle ☺️

    • @pavelukraine4929
      @pavelukraine4929 4 роки тому

      @@harfianashari2704 There is written exactly the same what he said

  • @langparisse9185
    @langparisse9185 5 років тому

    Where can I find this table?

    • @langparisse9185
      @langparisse9185 5 років тому

      Chart for using stiffness modifier in structural analysis & design

  • @mohammadismail3970
    @mohammadismail3970 5 років тому +1

    Thank you Bhai

  • @bijoychondojony8800
    @bijoychondojony8800 5 років тому +1

    thanks man

  • @veerappan1000
    @veerappan1000 5 років тому

    Thanks a lot

  • @ahasanahmed7099
    @ahasanahmed7099 5 років тому

    Thanks a lot bhai...

  • @mdtariqulislam2795
    @mdtariqulislam2795 5 років тому

    thanks

  • @asim3n3
    @asim3n3 5 років тому

    Thanks for this informative video, but I have a concern regarding deflection and drift check as per UBC it is mentioned as following:
    UBC 1997
    1630.1.2 Modeling requirements:
    The mathematical model of the physical structure shall include all elements of the lateral force-resisting system. The model shall also include the stiffness and strength of elements, which are significant to the distribution of forces, and shall represent the spatial distribution of the mass and stiffness of the structure. In addition, the model shall comply with the following:
    1. Stiffness properties of reinforced concrete and masonry elements shall consider the effects of cracked sections.

    • @Decodebd
      @Decodebd  5 років тому

      What is the concern?

    • @asim3n3
      @asim3n3 5 років тому

      @@Decodebd concern is if the code say that members need to be cracked then how can to we check the deflection using without modifying stiffness.

    • @Decodebd
      @Decodebd  5 років тому

      Check the tutorials carefully. We have stiffness modifier(1.43 times of Stiffness modifier for Ultimate condition) to consider cracked sections for serviceability checks.

    • @asim3n3
      @asim3n3 5 років тому

      @@Decodebd thank you.

    • @Decodebd
      @Decodebd  5 років тому

      Wc