haro0n

Sir I did that and there are some problems First u said that end offsets for all frames are = 0 (because you need moment at c/c of beam & col not at face or distance d as in design) how can I do this?? I did this like. Select all >assign>frame/line>end length offsets> there are two options automatic from conectivity and the second one is define lengths?? Previously I use this option at end before analyzing and select the first opiton that is automatic from conectivity is this right? And now for this problem how can I make the end offsets =0?? I did by 2nd option placed 0 there. well u have membrane slab and you are meshing it? remove the meshing and see the results you will find 625 lb/ft on your longer and shorter beams for live load... (Display>Show Loads>Live) sir I am still confused with this shell, memberane and plate, where to use slab as a shell , where memberane and where plate?? And if we define slab as membrane then why we donot do meshing?? remember it will distribute load by 45 degree method you despite that your slab is 10x20 (1way and your short beams will carry nothing) but if you do it by 45 degree your short beams will also have 625lb/ft load for live loading... I did this in another way like this, 10x20=200 so ¼ of this 200ft^2 will be for shorter beams that is 50ft^2 so 25 for one shorter beam and 25 for other so our live load is 125 so for shorter end beam 125 x 25/10=312.5 lb/ft udl for shorter end beam. For longer beam xied it with 75ft^2.. 625 lb/ft will be triangular load so we have to convert it into udl then use it. The way I am doing is right?? If found it very easy so doing by this. you said results matched with moment distribution method...on ELEVATION 1 but not on ELEVATION A no I solved mdm only for elevation A and for elevation 1 I use ACI moment coefficents. Can I use the moment coffients for this shorter beam?? As here I have only 1 span and in moment coeffients there is no such condition. you have single frame 1 beam and 2 columns...just make the columns straight and you will have 3 span continous beam...thats it..solve it by moment distribtuion method... solving for mdm for beams? In this case the loading will only be on the center beam so result will be same. As in this condition.. one more thing that previously u said that apply modifiers at end now I do by this way but after analyzing if I want to check those modifiers then I cannot see them as if I apply them while defining setions then after anayzing there are still shown there?

Assalam u alaikum rana sir as u said that design manually so I made a simple frame structure and did it manually then I model it in etabs and compare the results and I was happy that most of them matched but there is some problem that for shorter beams my results are different as this is a single span so I did not solve it using ACI moments coefficients. First I solved it using direct formuals and also did it using Moment Distribution mtd but results are changed I want to know how these values came for shorter beam? and how software calculated this. as mine are different. And what I did that I first solve the slab then transfer its dead load and live load separately on the supporting long and short beams by tributory area then using ACI coefficient I solved the longer beams and results got matched but did not find way to solve the shorter beams so solved it using direct formulas nd other methods but results were change. Then from beams I transferred the loading and moments to colums and sloved the col also. E.g for end columns where longer and shorter beams is meetng I took the greater moment which was negative moment of longer beam and used it. For axial load I transferred the loading and multiplied it with half span of the beam in conection with that column. image and file is attached. Same for elevation B. its value is also change. The attached image is the values for Moment 3-3. If I use wl^2/8 for this shorter beam then Mmax is 12.62 kip ft. my calculated factored load per unit length is 1.01 k/ft for this shorter beam whhich is Shown above so If I select Moment 2-2 values then for this end column it shows the moment to be 12.24 close to my value. But here it shows totally change values. Similarly for center short beam where tributory area is doulbe then this. Solving it by wl^2/8 gives close value for moment to be transferd on the center column. As the negative moments from longer beams will be canceled out. thanks in advance edb file + imagel.rar

thats very nice sir umar

thanks for it its very tidy work and i think these are automatic posts i mean bots so if they are deleted i mean their id then it will be ok. sir umar will be busy he is also not on the forum

its my request to moderators that some spamers are coming on this site and making alot of posts every where so do something for them otherwise more and more will come in future and will make spam posts...

sir first of all thnks for replying in that much detail. and yes i have started this so inshALLAH it will keep this going. and i am in my final year 7th smstr. i am also doing this manually and i want to compare it with etabs for that reason i am doing it in etabs but i can compare it when i will do it correctly in etabs so thats why i shared it here so that i came to know how to do it correctly as if i dont do it correclty then results will not match. u pointed alot of things and i have started working on it but its really very difficult after reading about different thing here on SEFP i came to know that i knows nothing about structurl engrg its very tought.. one of our teacher taught us about this so i did it in that way plus other help taken from differnt soucres and i am combining that all so thats why there r mistakes about applying modifiers, assigng slab as shell etc . sir i have noted these all and also doing it manually nd will return back after that with more questions thnks again 4 ur time

Assalam o alaikum I am attaching a model which I have made in etabs. This was the assignment which teacher gave us to design it. I have designed it in etabs this is my first model and need your guidence I want to know whether its acceptable or not??? If I need to revise it what things I should change.?? Also after designing we can see longitudinal steel, shear reinforcement etc.. this is different for each section so how I can use these to select the bar reqirement, spacing e.t.c as we have one section plan for beam and column etc. but this is different for all sections so how I select this for column, beam et.c what about slab?? Its reinforcement etc.. I used property modifiers and other tips also which I found on this site so kindly guide me. Details of the building r as follows. 4-story building X-direction spacing = 6 @10 feet Y-direction spacing =2 @20 feet One way slab Load is assigned using Shell/area loads ( I selected all panels of one story then applied the shell/area load dead, live et.c then for next story) but the load is not fully transferred to column etc, why? After analyzing the stress diagram looks odd to me. Rcc wall is used in basement. Auto meshing is done 4x4 Seismic effect is not taken into account so only one load combo is used. I deleted the others but after analysis they were shown why?? How I will know that any member is failing and I need to change it?? In final design we show the bar, spacing, etc but as I mentioned it is change for every sections so how I should finalize this for column beam and what for rcc wall?? After analysis it looks like that no load is transferred to it.. Kindly check this model by performing manual checks on it. Waiting for ur response. want to learn from ur experience thanks in advance assignment.rar

thanks rana bro its cleared now u defined it in simple way

thanks bro let me check

In etabs we define mass source frm there we select from load and then we define differnt loads like dead , live etc my question is that what is use of this "mass souce" we donot apply it in the structue then where we need it?? and which loads are defined here means dead, live and which are not defined?? Thanks

rana bro 4shared links are not working it says invalid links i thnk file has been deleted kindly update them thanks

thanks alot sir u solved my problem i was confused with it. took help from internet but it confused me more so i posted it here thnks for it

salam i have problem related to defining concrete material i have attached the image. its shown there that mass per unit volume of concrete is 2.24 and weight per unit volume of concrete is 8.68 while the units are kip-in. and fc'=4ksi. i want to know how both these value comes?? and if fc'=3ksi then what will be the values of these two?? i-e mass per unit volum nd weight per unit volume???

most of the subjects which are taught in bsc level are related to structure like mechanics, tos 1, tos 2, strength of materials, rcc, design of steel strctrs, computer application, so most of the students go for structure but as waqar bro said that there is saturation in structure so i also think the same way and we should now go for other fields, so i have selctd geotec

nice topic started @waqar bhai but still there is no senior to work on this .. may be we get some but most important is to share this idea with more and more engineers so that they know about this...