Module 3: Analysis of Statically Determinate Structures - Examples

The set progresses from support reactions and diagram relationships to truss, cable, and arch problems. All solutions use equilibrium and the structural idealizations developed in the companion lesson.

Example 1: Simply Supported Beam with an Eccentric Point Load

A 10 m10\text{ m} simply supported beam carries P=50 kNP=50\text{ kN} at 4 m4\text{ m} from the left support AA. Find AyA_y and ByB_y.

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 2: Cantilever with Uniform Load

A 6.0 m6.0\text{ m} cantilever carries w=15 kN/mw=15\text{ kN/m} over its full length. Determine the vertical and moment reactions at the fixed support.

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 3: Shear Change under a Uniform Load

A beam segment from x=0x=0 to x=4 mx=4\text{ m} carries w=8 kN/mw=8\text{ kN/m} downward. If V(0)=25 kNV(0)=25\text{ kN} using the lesson sign convention, find V(4)V(4).

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 4: Moment Change from a Linear Shear Diagram

Over a 5.0 m5.0\text{ m} beam segment, shear varies linearly from +20 kN+20\text{ kN} to −10 kN-10\text{ kN}. If M(0)=12 kN⋅mM(0)=12\text{ kN}\cdot\text{m}, find M(5)M(5).

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 5: Internal Hinge in a Multi-Span Beam

An internal hinge separates a beam into left and right segments. The left segment has a known downward load of 30 kN30\text{ kN} and a support reaction of 18 kN18\text{ kN} upward. Determine the vertical hinge force acting on the left segment.

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 6: Zero-Force Member by Inspection

At an unloaded truss joint, members ABAB and BCBC are collinear and a third member BDBD is non-collinear. No support reaction acts at the joint. Determine FBDF_{BD}.

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 7: Method of Joints for a Right-Triangle Truss

At a truss joint, a 100 kN100\text{ kN} downward load is resisted by a horizontal member and a diagonal member with a 33-44-55 geometry. Find the diagonal force and the horizontal member force, assuming both unknown forces act away from the joint.

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 8: Method of Sections

A truss section cuts three unknown member forces. Two of their lines of action intersect at point OO. External loads on the isolated side create a net clockwise moment of 240 kN⋅m240\text{ kN}\cdot\text{m} about OO. The third cut-member force FF has a perpendicular lever arm of 3.0 m3.0\text{ m}. Find FF.

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 9: Symmetric Parabolic Cable

A cable spans L=40 mL=40\text{ m} with central sag f=5.0 mf=5.0\text{ m} and carries w=6.0 kN/mw=6.0\text{ kN/m} uniformly per unit horizontal length. Determine the horizontal component of cable tension.

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 10: Maximum Tension in the Same Parabolic Cable

For the cable in Example 9, determine the support vertical reaction and the support tension magnitude.

Step-by-Step Solution

0 of 3 Steps Completed
1

Example 11: Three-Hinged Arch Horizontal Thrust

A symmetric three-hinged arch spans 20 m20\text{ m} with crown hinge rise 4.0 m4.0\text{ m}. A 60 kN60\text{ kN} point load acts at midspan directly over the crown. Determine the vertical reactions and horizontal thrust.

Step-by-Step Solution

0 of 4 Steps Completed
1