08.01.2013 Views

Steel Designers Manual - TheBestFriend.org

Steel Designers Manual - TheBestFriend.org

Steel Designers Manual - TheBestFriend.org

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

This material is copyright - all rights reserved. Reproduced under licence from The <strong>Steel</strong> Construction Institute on 12/2/2007<br />

To buy a hardcopy version of this document call 01344 872775 or go to http://shop.steelbiz.<strong>org</strong>/<br />

<strong>Steel</strong> <strong>Designers</strong>' <strong>Manual</strong> - 6th Edition (2003)<br />

306 Introduction to manual and computer analysis<br />

Fig. 9.19 Flexibility coefficients for a loaded beam<br />

ment response at a number of locations will now be obtained by considering the<br />

beam sketched in Fig. 9.19.<br />

Considering a unit load acting at point 1 (Fig. 9.19(b)), the corresponding deflections<br />

at points 1, 2 and 3 are denoted as f11, f21 and f31 (the first subscript denotes<br />

the point at which the deflection is measured; the second subscript refers to the<br />

point at which the unit load is applied).The terms f11, f21, f31 are called flexibility coefficients.<br />

Figure 9.19(c) and (d) give the corresponding flexibility coefficients for load<br />

positions 2 and 3 respectively. By the principle of superposition, the total deflections<br />

at points 1, 2 and 3 due to P1,P2 and P3 can be written as<br />

D1 = P1f11 + P2f12 + P3f13<br />

D2 = P1f21 + P2f22 + P3f23<br />

D3 = P1f31 + P2f32 + P3f33<br />

Written in matrix form, this becomes<br />

ÏD1<br />

¸ Èf<br />

f f<br />

Ô Ô<br />

ÌD<br />

2 ˝ =<br />

Í<br />

f f f<br />

Í<br />

Ô<br />

ÓD<br />

Ô<br />

3 ˛ ÎÍ<br />

f f f<br />

11 12 13<br />

21 22 23<br />

31 32 33<br />

˘ ÏP1<br />

¸<br />

˙ Ô Ô<br />

2 ˙ ÌP<br />

˝<br />

˚˙<br />

Ô Ô<br />

ÓP3<br />

˛<br />

(9.14)

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!