## Problems Method ofSections and Joint Resolution

Determine the support reactions and the forces in the members of the pin-jointed frames indicated by the '*' in Problems 3.1 to 3.4 using the method of sections. Problem 3.1 Problem 3.2 Problem 3.3

### Problem 3.4

Determine the support reactions and the forces in the members of the pin-jointed frames indicated in Problems 3.5 to 3.10 using the method of joint resolution.

Problem 3.5  Problem 3.6  Problem 3.8 Problem 3.9

12 kN

12 kN Problem 3.10

Pin-jointed frames 85

3.3.2 Solutions: Method ofSections and Joint Resolution Sol ui io ii

Tti|>ic: I'i it J ui ill inI f-"r .liii ck - Mcl h d<I of ficcl i cuts

Consider scclion y-y through incmlKrhi (J), llll. [Ki and Hi, l&ttW Tl.iikM

+ 2^75 _ JO.O - 40.0 + 71,25 + (44.2 * Sin 45°) + - 0

Ikadifs slwxild cculdtf ilk- equilibrium of tie rtghl-luiid-iidt of (hi sections nud y-y m<I tcnillnii the value; IbrlliL- unliiitmn ifbflfti ¿'m; JulI f'q[;             Solution

Tupic: rin-Jniiik'rt Frames - J »¡u I Krai In [¿on IVOIJIcpu NumW; ¿9

21371

StibsliUUu fm fja in KqiHLLiun (b) + 3.5 + [23.J7I - 3-Oftf) SiH? +■ Fa Sin a = 0

+2,5 + [(22.371 * fl-SW) - <2.DFW * 0.894)+(ft, x 0.447) = 0 > ,

Coiiiiilirjoinl E5:

ILWIfl {fctrui)

It.liKM

S (2,^,59) = M4J Cos/f- (SjWLMfl = Sinf (3,5/3.536) - 0,707 Cosj'- (2,5/3.536) - 0,707

from Equation (b):

Put = +■ (11.J9 CospJCmy) = + ((IS ,39 * 0,39-1 W,707)] From l:.L|ii;uion (;i):

Cmisukr juinl C:

liltfi

IfUi