Shawn Kenny, Ph.D., P.Eng. Assistant Professor Faculty of Engineering and Applied Science Memorial University of Newfoundland ENGI 1313 Mechanics I Lecture 34:Analysis of Frames and Machines

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 2 Lecture 34 Objective to illustrate the analysis of frames and machines by example

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 3 Example The scale consists of five pin-connected members. Determine the load W on the pan EG if a weight of 3 lb is suspended from the hook at A.

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 4 Example (cont.) Any Structural Characteristics?  Two-force members EC FD G

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 5 Example (cont.) FBD  ACD  EG  FH CyCy GyGy W DyDy HyHy GyGy HxHx ByBy BxBx A y = 3lb CyCy DyDy

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 6 Example (cont.) Known? AyAy Find? WW How?  Successive equilibrium equations and substitution EyEy GyGy W ByBy BxBx A y = 3lb CyCy DyDy FyFy HyHy GyGy HxHx

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 7 Example (cont.) FBD ACD  EG  C y = E y FBD ACD  FH  D y = F y GyGy W ByBy BxBx A y = 3lb CyCy DyDy HyHy GyGy HxHx CyCy DyDy

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 8 Example (cont.) FBD ACD ByBy BxBx A y = 3lb CyCy DyDy

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 9 Example (cont.) FBD EG GyGy W CyCy

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 10 Example (cont.) FBD EG GyGy W CyCy

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 11 Example (cont.) FBD FH HyHy GyGy HxHx DyDy

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 12 Example (cont.) FBD ACD ByBy BxBx A y = 3lb CyCy DyDy

ENGI 1313 Statics I – Lecture 34© 2007 S. Kenny, Ph.D., P.Eng. 13 References Hibbeler (2007) mech_1