The back of the channel steel deviates from the 30mm. The upper and lower iron plates are welded at intervals. Is the cross section resistance moment the sum of the two? No, is it big or small? Thank you
The direction of the X axis distance of the centroid and centroid of single channel and two channel combination from coincidence (the same), so the moment of inertia of the two combinations of two single channel channel is equal to the moment of inertia and resistance moment and is also. (resistance moment = moment of inertia / centroid distance)The Y axis direction, back to the departure from the 30mm two, the centroid distance than the centroid of the single channel combination channel distance increases 15mm, moment of inertia is the centroid distance square by channel section, so a combination of two channel resistance moment is far greater than the two single channel and.
The back of the steel channel deviates from the 30mm, and the upper plate and the lower iron plate are welded at intervals. Is the cross section resistance moment the sum of the two?" Must be greater than or equal to the sum of the two.
Elder brother?! The general channel without you so used, if used together with 2 channels, to groove is used, it can not be like you said with the back to back, with the flexural performance of steel greatly reduced so that you see the cement rod, hollow slab, steel pipe was use, so as to get more with less weight material bearing.
You must be stronger than this one, nor is it the sum of the two forces, because the attitudes of the two channels are different. But much less than the way I use it.
