Forces in an indeterminate truss Comparison of forces in statically determinate and statically indeterminate trusses Features - comparison of forces in statically determinate and indeterminate trusses - bars with strain gauge measurement to measure bar force Learning objectives/experiments - measurement of the bar forces in a statically determinate and a statically indeterminate, 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 measuring results with mathematical methods -- method of joints -- Ritter’s method of sections - basic principle: measurement of forces using strain gauge measurement Specification [1] investigation of bar forces in statically indeterminate trusses [2] surplus bar, longitudinally adjustable [3] straight and inclined loading possible [4] load application device with force gauge mountable on different node disks [5] measuring point to measure force on each bar [6] measuring amplifier FL 152 required [7] GUNT-software in FL 152 to evaluate measured values graphically [8] storage system to house the components [9] experimental setup in frame SE 112 Technical data 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 - measuring point on each bar - height of truss max. 270mm - length of truss max. 500mm Load application device - ±500N - graduation: 10N Dial gauge: measuring range: 0...20mm LxWxH: 1170x480x178mm (storage system) Weight: approx. 22kg (total)