Features
Comparison    of    forces    in    statically determinate and over-determinate trusses
Bars with strain gauge full bridges to measure bar force
Optional Computerized evaluation of experiments
Over-determinate trusses are employed where over-dimensioning is purposely required because safety must be maintained in the event of failure of an element, such as in aircraft construction. With additionally inserted bars a statically determinate truss becomes internally statically indeterminate. In this case the truss is termed statically over-determinate.
Tesca Forces in Over-determinate Trusses experimental set-up permits investigation and comparison of statically determinate and statically indeterminate trusses. Using the bars and node discs, a statically determinate, single plane truss is first constructed. On installation of a surplus bar the truss becomes over- determinate. By way of a load application device, straight or inclined forces are applied to the truss, thereby simulating various load cases. The occurring tensile and compressive forces in the bars are recorded by means of strain gauges. Computerized evaluation can be optionally provided by measuring amplifier. The software is used to manage the measurement data and provide graphical representation of the bar forces. The software features a comprehensive help function.
All the component elements of the experiment are clearly laid-out and housed securely in a storage system. The complete experimental set-up is arranged in the frame.
The well-structured instructional material sets out the fundamentals and provides a step-by- step guide through the experiments.

Specifications
Investigation of bar forces in statically over determinate trusses
Surplus bar, longitudinally adjustable
Straight and inclined loading possible
Strain gauge to measure force on each bar
Measuring amplifier
Software (optional) to evaluate measurement data
Storage system to house the components
Experimental set-up in frame

Technical Specifications
Bars: 8
5 bars, fixed 300mm
2 bars, fixed 424mm
1 bar, adjustable 400...450mm
Angle between bars: 30°, 45°, 60°, 90°
Maximum bar force: 500N
Strain gauge on each bar
Height of truss max. 270mm
Length of truss max. 500mm
Load application device
-  500...+500N, graduations: 10N
Dial gauge: measurement range: 0...20mm

Experiment Possibilities
Measurement of the bar forces in a statically determinate and statically over-determinate, single plane truss
Distribution of forces in the single plane truss dependent on the use of a surplus bar
Dependency of the bar forces on the external force
Magnitude, direction, point of application
Comparison of  measurement  results  with mathematical methods
Method of joints
Ritter’s method of sections
Basic principle: measurement of forces using strain gauges

Scope of Delivery
1 set of bars
5 node discs
1 load application device
1 set of cables
1 software CD (optional)
1 storage system with foam inlay
1 set of instructional material