DISK. U068-8BCT10N OF i 1 13 



of the flange. The depth k (called the effective depth) 

 inula (I) U obtained by taking the groat area of 



!"'tli flange in com|)uting the location of the 

 gravity of ih. flanges. 



It should be borne in mind that if then* is DO lateral 

 deflection of tin- top flange that its maximum unit stress 



deperni> mtin ly <>n -, th.- M>rti..n modulus, as it b tome- 

 times called. While riv.-t iml. , afTert the position of the 

 neutral axis for the sections in which tin y ..r.-ur. probably 

 two-thirds or one-half of the length of a girder \\ill be 

 undiminbdied hy holes, hence in applying thr formula 



Of 



A/- to check the results of formula (1) it will be best 



to determine the position of the m utral axis from the 

 gross section, and find the moment of inertia of the net 

 section of the entire girder section for / in the formula. 



PROBLEMS 



3<j. Compute the probable maximum unit strtas in the 



SI 

 of the girder of Prob. 26, by means of the formula If - . 



36. Comput, th,- probable maximum unit atrras in the 

 flange of the girder of Prob. 2c, by means of the formula M -~. 



3r. Compute the probable maximum unit Mreai in the i mupn Mion 

 flanges of Probe. 3a and 36, by means of the form ula A/ - . 



