AISC brant pdf free download

AISC brant pdf free download.A General Solution for Eccentric Loads on Weld Groups.
The papers by Tide 5 and by Butler et al 3 indicate that solutions have been obtained using computer programs. Butler states that the method is general, but shows details for only a C-shaped weld subjected to loading parallel to a principal axis. Tide shows results for a pair of parallel line welds and a C-shaped weld with the loads again parallel to principal axes. The AISC tables include a pair of parallel line welds, rectangular box welds, C-shaped welds, and L-shaped welds; loads are parallel to a principal axis in the first three types and parallel to a leg of the L in the last. In a previous paper, 6 the author showed how rapid solutions could be obtained for any eccentrically loaded bolt groups. The same method can be extended to weld groups. In essence, the method involves: 1. Directly finding the instantaneous center corresponding to elastic behavior of any weld arrangement for any eccentric load. 2. Directly determining the elastic solution for the maximum permissible load. 3. Directly determining an approximate value for the ultimate load. 4. Iterating to improve the approximate value. 5. Using the same procedure described by Tide to convert the ultimate load to an allowable load consistent with the AISC tables. Inasmuch as welds are continuous, it is necessary to discretize into a finite number of weld elements. A moderately large number of discrete elements is required if reasonable accuracy is to be achieved, so the rather long procedure for each weld element described above probably makes the procedure too laborious for manual calculations. Accordingly, the procedure is given here as a FORTRAN computer program. (See Appendix.)Computations for the Elastic Solution —The length of each weld element, W, is calculated, and using these discrete elements, the centroid is located, the polar moment of inertia, J, is calculated, and the moment, M o , of the applied unit force about the centroid is calculated. A mapping function called FACTOR is used to transform forces to distances and it is equal to J divided by the product of the total length of weld and moment M o . The instantaneous center is located by adding to the X and Y coordinates of the centroid the quantities –P y × FACTOR and +P x × FACTOR, respectively. The radius vector, D to the center of each weld element is calculated, and the largest one noted. The allowable moment about the instantaneous center of all elemental forces is ∑ WD 2 /D max times the allowable force per inch of weld. The allowable (elastic) load is that moment divided by the moment of the applied unit force about the instantaneous center. This load and the identification number of the critical weld element are printed.Computations for the First Approximate Ultimate Load—The instantaneous center located above is used as the first trial center. Calculations follow the procedure attributed to Butler 3 described earlier in this paper. (Angle θ is determined as follows: Form the dot product of the radius vector and the weld element vector. Divide this by the product of the magnitude of the two vectors; this quotient is the cosine of the angle between the vectors. Its complement is angle θ .)AISC brant pdf download.