{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Class 3AT - ENGR 111 Week 2 ~ Monday Class 3 T Pollock Fall...

Info iconThis preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
1 ENGR 111 Week 2 ~ Monday Class 3 T. Pollock Fall, 2009
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 Is this a truss? Is it statically determinate? All joints are pinned . Fixed restraint Rolling restraint (support) (support) (nodes)
Background image of page 2
An assembly of bars with pinned ends can only transfer forces in the direction of the long axis of the bar. Truss links (bars)
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
An unconstrained bar aligns itself in the direction of an applied force.
Background image of page 4
Conversely, if the ends of the bar are constrained, the force aligns with the bar. This is easiest to see if the bars are cables in tension. cables
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Statically determinate: We can write three equations describing the forces in the plane of the paper: Σ Fx = 0 Σ Fy = 0 Σ Mz = 0 Therefore we can solve for only 3 unknowns.
Background image of page 6
A sketch of a structure, or any portion thereof, that shows the forces rather than the physical details is called a Free Body Diagram .
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
8 All joints are pinned . Is this a truss? Is it statically determinate?
Background image of page 8
With two fixed joints, there are four unknowns, but only 3 equations. Σ Fx = 0 Σ Fy = 0 Σ Mz = 0 Statically indeterminate.
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
10 Is this a truss? Is it statically determinate?
Background image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}