LRFD

"How can design a simple beam both fix end for 2 kn / m ULD .. by LRFD ?? "

<Acronyms.com> lists 56 different ULD definitions. What does your mean?

It has NO listing for LRFD ! What does yours mean?

". pls help"

LRFD = load resistance factor design is a method in steel construction design , and the UDL =uniformed distributed load .

I have to design a beam a rectangular hallow section for 10 m long with a LRFD , I have a problem in starting with that methods .

I ma sorry for not clarify it in that post . thank you for you effort to help ,

This is a classical Simple problem.

But what do you finally arrive at?

1. Minimum possible mass of steel using standard hot- rolled Sections of which standard? Rectangular hollow meaning 2 Channels-- same size all 10m? Only welded-no prestressing?Say at 50% margin to Yield stress( all cases below)?

2 Minimum possible mass of steel using optimum VARIABLEcross section of box end to end . Using standard structural carbon steel plate (name your standard). No Prestress.

3 Minimum possible mass of steel using the strongest Duplex SS plate(Cost no consideration)

4 Same as 3above but with the best prestress practice.

MUKULMAHANT

Thank you for your replay . interesting idea to use the channel section ,

In fact I use the British code . I was about to use a RHS ( rectangular hallow section ) steel tube hot rolled section . both end fix . after we find the moment of inertia and the BMD ( bending moment ) diagram . and the SFD share force diagram . how can I find the corrected section to chouse , by the LRFD ( load resistance factor design ) I don't have the processed steps mathematically to use . I am looking for manual design by hand or a step by step procedure for this problem .

MUKULMAHANT

Thank you for your replay . interesting idea to use the channel section ,

In fact I use the British code . I was about to use a RHS ( rectangular hallow section ) steel tube hot rolled section . both end fix . after we find the moment of inertia and the BMD ( bending moment ) diagram . and the SFD share force diagram . how can I find the corrected section to chouse , by the LRFD ( load resistance factor design ) I don't have the processed steps mathematically to use . I am looking for manual design by hand or a step by step procedure for this problem .

Anyone with a medium amount of intelligence would define his subject clearly and not use acronyms......and make sure that it is fully readable and understandable too....

Remember, people who know little or nothing (about anything), often hide behind acronyms to give the impression that they know more that they actually do......

.....is that the case here?

Andy

in every engineering category there are a well known expression or acronyms , and its well known in structure engineer , but I agree I have a little knowledge in that issue , and I think this forum is about to help people with such like this problems , otherwise not defined them as hiding . and I still waiting for you help .

LRFD is extremely clear to a civil design engineer who deals with structural steel, or works with the international building code, uniform building code, etc.. this is a very common acronym amongst practicing civil engineers, and is used in Text more frequently as the acronym than fully speeled out. Many Civil engineers may not even know what LRFD stands for, just what the acronym means with regards to engineering of structures.

You should look for the AISC LRFD Manual. While the structural calculations are straight forward, you must know the load resistance factors to apply to determine the applied load conditions you must satify. These depend on things like the use of the structure, and environmental conditions the structe may be exposed to like dead load, live load, seismic load, snow load, and wind load. there are also materials strength factors, resistance factors, that need to be accounted for in the calculations to allow for acceptable variations in materials quality.

Sadiq,

Regarding your posted topic, you can use STAADPro 2005 or latest version, it has a built in LRFD design method under the Design Parameter, you can model your project and analyze it thru the modelling process, just make sure that all the external data you have entered are all in accordance with the prevailing code in you place then you can select the specific design parameters and it will give you the most economical section.

Grateful for you are post . in fact I am a user for staad pro . but I wonder what is the easterly step by step mathematically to solve that problem .

I was about to use a RHS ( rectangular hallow section ) steel tube hot rolled section . both end fix . after we find the moment of inertia and the BMD ( bending moment ) diagram . and the SFD share force diagram . how can I find the corrected section to chouse , by the LRFD ( load resistance factor design ) I don't have the processed steps mathematically to use . I am looking for manual design by hand or a step by step procedure for this problem .