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Q2. A point load of 2.236kN is applied at point 3 of a frictionless pin- jointed structure which consists of members as shown in Fig Q2. Displacements at point 1 are fixed in x and y directions whereas only displacement in y direction is fixed at point 2. Member 1 has end points 1 and 2, member 2 has end points 2 and 3 and member 3 has end points 1 and 3. The cross sectional areas of member 1, 2 and 3 are 500 mm?, 250 mm² and 1414.42 mm respectively. Length of both member 1 and 2 is 10 m. Young's modulus (E) for all members is 200,000 N/mm². 2.236 KN 117 2 Fig 22: Pin-jointed structure (a) Write down element stiffness matrix for each member and assemble the global stiffness matrix for the whole structure. (b) Calculate horizontal and vertical displacements at point 2 and point 3. Element stiffness (ke) matrix of a pin-jointed element is: cos sin [14.1+(421 sino coso 4E cos sin e L -coso L-cos Osin 0 - cos o - cos sin cose cos Osino - cos sin e -sino cos sin sino - cos sin e -sino Subscript 'e' stands for element, L is length of an element, is the angle of inclination of the element measured anti-clockwise from the X-axis.