conjunction with this code, allowable bending stresses in compression (FCY Table 11CIndian Steel Design IS Parameters. The design concept is totally changed in comparison to earlier code IS which is based on Elastic method. In view of this, an effort has. Now this time I am come with IS code of Design of Steel Structure. This code is allowed for Polytechnic Diploma in Civil, soundofheaven.info
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Is (Rerfflrmed ). Indian Standard. CODE OF PRACTICE FOR. GENERAL CONSTRUCTION, IN STEEL. (First Revision). Sixtcmtb Reprint MAY . Scope of IS Indian Standard Code. IS Indian Standard applies to general construction using hot rolled steel sections joined using riveting, bolting and welding. This Indian Standard (Third Revision) was adopted by the Bureau of Indian Standards after the draft. IS - Download as PDF File .pdf), Text File .txt) or read online. Indian Standard CODE OF PRACTICE FOR GENERAL CONSTRUCTION IN STEEL.
Part 1 Fusion welding of steel Part 1 Approval tests for weldersswhen welding procedure is not required: E -mail: In cases where this method of design is employed. If the struts carry. Australian Institute of of beams.
IS The standard was revised in and subsequently in , incorporating certain very important changes. IS is the basic Code for general construction in steel structures and is the prime document for any structural design and has the influence on many other codes governing the design of other special steel structures, such as towers, bridges, silos, chimneys, etc.
Realizing the necessity to update the standard to the state of the art of the steel construction technology and economy, the current revision of the standard was undertaken. The revised standard will enhance the confidence of designers, engineers, contractors, technical institutions, professional bodies, and the industry and will open a new era in safe and economic construction in steel.
Tweet Share Share Share Share. Loading devices shall be previously calibrated and care shall be exercised to ensure that no artificial restraintsiare applied to the prototype by the loading systems. The geometrical. Unless otherwrse specified. Stiffened flanges shall include flanges composed I-sections or of plates with continuously stiffened edges.
Z-sections stems of tee sections and The width ofthe outstand of members referred above shall be taken? W Width of Outstand Distance from the free edge to the first row of rivets or welds Nominal width Half the nominal width Flange of beam and tee sections 3. NOTE 3 as follows: Plates Angle.
In this rule. In such cases strength is not usually governed by lateral buckling. However where the width exceeds 60 T1. In calculating the area to be deducted for rivets. O mm in excess of the nominal diameter of the rivet unless specified otherwise. The chain of lines shall be chosen to produce the maximum such deduo tion.
In a built-up member where the ual parts do not correspond with the critical whole. C and D FIG. For non-planer sections. These provisions do not apply to the webs of Indian Standard rolled steel joists and channels or to packings. Except where the provisions of subsequent clauses in this section require thicker elements of members. While considering the simultaneous effects of vertical and horizontal surge loads of cranes for the combination given in 3.
Except as specified in 3. When secondary effects are considered together with wind or earthquake. For constructions where secondary effects are considered without wind or earthquake loads. When the effect of the wind or earthquake load is taken into account.
Erection loads 3. Where co-existent bending and shear stresses are present. For members of steel with yield stress MPa and over. The following provisions shall also be considered while determining the permissible stress in members subjected to fluctuations of stress: Discontinuities such as bolt or rivet holes.
The value off max shall not exceed the permissible tensile or compressive fatigue stress as determined from IS: The fatigue cracks are caused primarily due to stress concentrations introduced by constructional details.
All details shall. Except where specificaily stated to the contrary. For members of steels with yield stress below MPa.
Care shall be taken to avoid sudden changes of shape of a member or part of a member. The foundations of a building or other structure shall be so designed as to ensure such rigidity and strength as have been allowed for in the design of the superstructure. Therefore earthquake forces applied at the centre of gravity of all such components of loads transfer to the foundation should be ensured see IS: Columns also should be tested for proper anchorage to the trusses and other members to withstand the uplifting effect caused by excessive wind or earthquake pressure from below the roof.
Where the connections to the interior columns are so designed that the wind or earthquake effects are traniferred to the interior columns also. To provide for torsional effects of wind and earthquake forces bracings in plan should be provided and integrally connected with the longitudinal and transverse bracings to impart adequate torsional resistance to the structure. Restoring moment due only O-9 times the dead load shall be considered. NOTE 2. The effect on the load from the deflected or deformed shape of the structure or of individual elements of the lateral load resisting systems.
All individual members of the structure which have been designed for their dead and imposed loads. Where a wall is placed eccentrically upon the flange of a supporting steel beam. The structure adjaent to the. For the purposeof g:. Expansionjoints shall be so provided that the necessary movement occurs with a minimum resistanceat the joint.
Where lug angles are used. Values of tr. The slendernessratio of a strut shah be calculated as the. The actualstrut length shah be taken as the length from the centrMo-centre of The effectivelength.
TABLE 5. Z ii: A method of determining the effective length of stepped columns is given in Appendix D. Where accurate frame analysis is not done.
In the case of members of trusses buckling in the plane perpendicular to the plane of the truss the effective length shall be taken as 1. The thickness of an outstanding leg of any member in compression shall be in accordance with 3. Effective length as given in Table 5. In the case of bolted. Where practical difficulties prevent this. Except as modified under 3.
In cases where the beam connections are eccentric with respect to the axes of the columns. The ends of compression members faced for bearing shall invariably be machined to ensure perfect contact of surfaces in bearing. In case where this ratio is exceeded. When the slab alone distributes the load uniformly. Where the end of the column is connected directly to the base plate by means of full penetration butt welds the connection shall be deemed to transmit to the base all the forces and moments to which the column is subjected.
Columns with slab bases need not be provided with gussets. All the bearing surfaces shall be machined t ensure perfect contact. Where full strength T-butt welds are provided no machining of contact surfaces shall be required. Table 5. The base plates and grillages of stanchions and the bearing and spreaders of beams and girders shall be of adequate strength.
The calculated average compressive stress shall not exceed the values obtained from. In no case. The use of steel castings shall be limited to bearings. If the struts carry. For determining the permissible axial and bending stresses. Single or double angle continuous struts.
Ili welded construction.
In riveted constrpction. The thickness of flat lacing bars shall be not less than one-fortieth of the length between the inner end rivets or welds for single lacing. For tension members under stress.
Laced compression members shall be provided with tie plates at the ends of lacing systems and at points where the systems are interrupted see also 5. Where practicable. Where welded lacing bars overlap the main members. Lacing bars. The welding shouid be sufficient to transmit the load in the bar and shall.
The riveting or welding of lacing bars to the main members shall be sufficient to transmit the load in the bars. The required section for lacing bars for compression membea or for tensionmembers subject to bending shall be determined by using the appropriate permissible stressessubject to the requirements in 5. If the column section ls subjected to eccentricity or other moments aboutl-y axis the battens and the column section should be specially designed for such moments.
The number of battens shall be such that the member is divided into not less than three bays within its actual length from centre to centre of connection. Tie plates shall be designed by the same method as battens. In no case shall a tie plate and its fastenings be incapable of carrying the forces for which the lacing has been designed. The effective depth of a batten shall be taken as the longitudinal distance between end rivets or end welds.
The main members shall also be checked for the same shear force -and bending moments as for the battens. The thickness of batten or the tie plates shall be not less than onefiftieth of the distance between the innermost connecting lines of rivets or welds.
C 2N the transverse shear force as defined above. Battens shall be of plates. When plates are used for battens. The length of weld and depth of batten plate shall be measured along the longitudinal axis of the main member. In addition. At least one-third of the weld shall be placed at each end of this edge.
The length of weld connecting each edge of the batten plate to the member shall. Where the members are separated back-to-back. Table 6 1C or 6. For an I-beam or channel with equal flanges bent about the axis of maximum strength X-X axis. For steels with yield stresses other MPa and MPa.
The maximum bending stress in tension cbt. The calculated stress in a member subjected to bending shall not exceed any of the appropriate maximum permissible stresses given in 6.
NOTE and 6. Tables 6. Coefficient K1 is defined in 6. D shall be taken depth of the girder at the point of maximum bending shall be taken as the effective thickness of the compression be calculated as: Tmean thickness of the compression flange.
TABLE 6. OO 1. Ibc MPa. Values of k.
If an elastic flexural analysis is not carried out. Values of kl for different values of are given in Table 6. Ix - Values of X and Y are given in Table 6. TABLE The maximum shear stress in a member having regard to the distribution of stresses in conformity with the elastic behaviour of the member in flexure. When loaded with the leg in compression. Guidance for calculqting references listed in Appendix E. IS I The maximum permissible bending stress in tension u.
The bending stress in the leg when loaded with the flange or table in compression shall not exceed Of. The average shear stress in a member calculated on the cross section of the web see The values rya for stiffened webs for a steel whose yield stress is not given in Tables 6. Where tongue plates see Fig. Where large apertures are cut in the web. Compliance requirements of 6. NOTE 1. The allowable stresses given in the Tables 6. For the minimum thickness of web stiffeners.
NOTE 3. I I 86 Fi Ei The effective span of a beam shall be taken as the length between the centres of the supports. The end restraint element shall be capable of safely resisting. Where the ends of the beam are not restrained against torsion. FICL 6. In arriving at the maximum flexural stresses. The effective sectional area of tension flanges shall be the gross sectional area with deductions for holes as specified in 3. The effective sectional specified in 6.
Each flange plate shall be extended beyond its theoretical cut-off point. Where two or more flange plates are used on the one flange. For this purpose the flange sectional area in riveted or bolted construction shall be taken to be that of the flange plate. The flanges of plate girders shall be connected to the web by sufficient rivets. Where splice plates are used. Xn welded construction. These butt welds shall deveIop the full strength of the plates.
Flange joints preferably should not be located at points of maximum stress. Where a Ioad is directly applied to a top flange. In the case of welded crane gantry plate girders intended carrying cranes with a lifting load of 15 tonnes or more. The gap between the web. For girders in exposed situations and which do not have flange plates for their entire length. The minimum thickness of web plates for different values are given in Table 6. In riveted construction. For other sections the maximum shear stress shall be computed from the whole area of the cross section.
The proportion of shear force. The effective cross-sectional area shall be taken as the full depth of the web plate multiplied by the thickness. The effective cross-sectional area for shear shall be taken as the full depth of the beam or channel multiplied by its web thickness.
In welded construction. When the thickness of the web is less than the limits specified in 6. NOTE -Where webs are varie in thickness in the depth of the section by the use of tongue plates or the Ii e. In no case shall the greater unsupported clear dimension of a web Dane1 exceed t nor the lesser unsupported clear dimension of the. This stiffener shall be designed so that I is not less than ds. These vertical stiffeners shall be designed so that I is not!
If the thickness of the web is made greater. Where horizontal stiffeners are used in addition to vertical stiffeners. This stiffener shall be designed so that I is not less than 4c. Where vertical stiffeners are required. Where single stiffeners are used. Intermediate vertical stiffeners may be joggled and may be single or in pairs placed one on each side of the web. I and t are as defined in 6. The stiffeners shall extend from flange to flange. When vertical intermediate stiffeners are subjected to bending moments and shears due to eccentricity of vertical loads.
For stiffeners subjected to external. Intermediate vertical and horizontal stiffeners not subjected to external loads shall be connected to the web by rivets or welds. Tn addition to the requirements of 6.
Load bearing possible. The radius of gyration shall be taken about the axis parallel to the web of the beam or girder. The stiff portion of a bearing is that length which cannot deform appreciably in bending and shall not be taken as greater than half the depth of beam for simply supported beams and the full depth of the beams continuous over a bearing.
For any section. The design and detailing of box girders shall be such The diaphas to. At points of support this requirement shall apply. Stiffeners shall be symmetrical about the web. The ends of load bearing stiffeners shall be fitted to provide a tight and uniform bearing upon the loaded flange unless welds or rivets designed to t ansmit the full reaction or load are provided between the flange and stiffener.
The bending stresses about the two axes should be determined separately and Open web purlins shall be designed as checked in accordance with 7. As an alternate to the general design procedure given in 6.
L shall be taken as distance centre-to-centre of the rafters or other supports of the purlins. The calculated deflection should not exceed those permitted for the type of cladding used. In calculating the bending moment advantage may be taken of the continuity of the purlin over supports.
Side and end sheeting rails shall be designed for wind pressures and vertical loads. The calculated deflections should not exceed those.
Fe S or Fe 4 W and slofies not exceeding. The maximum fibre stress shall not exceed the values specified in 6. The loads shall be assumed as acting normal to the roof in which case the bending about the minor axis may be neglected. Share this: Twitter Facebook. Like this: Like Loading Leave a Reply Cancel reply Enter your comment here Fill in your details below or click an icon to log in: Email required Address never made public.