دانلود مقاله ترجمه شده اندرکنش کمانش تیرهای باریک شده(یا با بال شیبدار)

There have been comparatively few studies of the elastic lateral buckling of braced or continuous tapered beams, and these are limited in their application. Lateral buckling is affected by the separate effects of moment distribution, taper, and restraints between adjacent segments

Moment distribution effects are commonly allowed for in design codes by using C_bm factors to multiply the classic lateral buckling moments M_u of simply supported uniform beam segments in uniform bending

Taper effects for linearly web tapered beam segments may conveniently be allowed for by multiplying the segment lateral buckling moments C_bm M_u computed using the mid-segment section properties by taper factors C_bt. Values of C_bt for a number of different segment moment distributions have been determined using a finite element computer program for the buckling of tapered beam structures

Lateral buckling of a braced or continuous beam is also affected the interaction between the segments into which it is divided by its braces and supports. One segment will be more critical than its neighbours, which will restrain the critical segment and increase its buckling resistance. The effects of restraints on buckling are commonly allowed for by using effective length factors to multiply the segment length used in the formulation of the elastic lateral buckling moment M_u of a uniform segment in uniform bending. Methods of determining the critical segment and of approximating its increased resistance developed for uniform beams have been adapted for web-tapered braced and continuous beams

This paper shows how these effects can be allowed for separately to develop good approximations for the elastic lateral buckling resistances of tapered braced and continuous beams. The accuracy of the approximations is demonstrated by comparisons with the predictions of the finite element computer program for the buckling of tapered beam structures