Category Archives: Statics

Real life reactions … and an engine block!

 

 OVERVIEW This series of exercises uses an engine hoist, four scales, and an engine block to allow students to predict (calculate) reactions and then measure them. This develops students’ confidence in their ability to calculate reactions and provides a great opportunity for “what if?” exercises. PRINCIPLE Reinforces static equilibrium and moment of a force. We […]

Zero Force Members

 

 Model Description This is a simple model that will demonstrate the use of zero force members (ZFM) in trusses. Wooden beams are attached with dowels to form a simple truss, which is acted on by an external force. The zero force members are identified by placing a load on a truss and then removing pins […]

Wooden Truss 3D

 

 Model Description This 3D model of a bridge is a model that is very close to a real representation of a bridge. It has a number of realistic features that cannot be shown with K’NEX or other simple structures.  This demonstration should take 15-20 minutes. Engineering Principle Bridges are more than just trusses put together. […]

Wooden Truss 2D

 

 Model Description This is a simple demonstration to introduce the basic principles of truss behavior and analysis. It will show how the shape of a truss—and not necessarily its weight/material—determines its stability. A simple truss design will be used to show that triangles are the important stability shape used in trusses rather than squares or […]

Wacky Fun Noodle

 

 Model Description This is a simple demonstration to show how tension and compression affect members of trusses. A wacky fun noodle (tube floatation device) will be used to demonstrate the effects of tension and compression on axial members. Students pull or push each end to display the desired behavior.  This demonstration should take 5-10 minutes. […]

Varignon’s I-Beam

 

 Model Description Introduce Varignon’s theorem to students as a simple way to determine the moment about a point. This demonstration should take 5-7 minutes. Engineering Principle Varignon’s Theorem states that the moment of a force is equal to the sum of the moments of that force’s components about the same point. where is the perpendicular […]

Uniformly Loaded Cables

 

 Model Description This is an opportunity to hang something from the ceiling and excite the students about their ability to analyze real world structures.  After a few weeks of statics lessons, students possess the ability to determine the maximum and minimum force in a cable suspension bridge through equations of equilibrium.   This demonstration should take […]

The Torque Tester

 

 Model Description This training aid provides an example of what the students already know intuitively about mechanical advantage and applied moment.  By using a dial torque wrench, units and physical measurement are readily observable and subject to discussion. This demonstration should take 5 minutes. Engineering Principle What You Need Item Quantity Description/Clarification Secure Bolt (Fig. […]

The Ski Gondola – Concentrated Cable Loads

 

 Model Description This physical model demonstrates how cables subjected to concentrated point loads establish equilibrium through geometry – i.e., the slope of each cable segment will change (as will the support reactions) as different loads are placed on the cable.  This demonstration should take 10-20 minutes. Engineering Principle Cables subjected to concentrated loads are a […]

The Persuader

 

 Model Description Use this daunting looking model to set the stage for a lesson on 3-D equilibrium and eventually persuade your students that it’s easier than it looks!  This demonstration should take 20 minutes. Engineering Principle 3-D equilibrium for a non-concurrent force system requires the simultaneous solution of six equations of equilibrium, three equations for […]