Q1: What is the forces in truss apparatus used for?
The FX-514 is used to measure the axial forces — tension and compression — in the individual bars of a single-plane statically determinate truss under an applied external load. Students construct the truss from the provided bars and node discs, apply a known force using the load application device, and record all bar forces simultaneously via strain gauge sensors and the LabVIEW DAQ software. The measured results are then compared against theoretical values from the method of joints and Ritter’s method of sections.
Q2: What is the method of joints and how does the FX-514 support its verification?
The method of joints is an analytical technique for determining bar forces in a statically determinate truss by applying equilibrium equations at each node in sequence. The FX-514 supports its verification by providing measured bar forces for the same truss configuration and loading, allowing students to compare the experimentally recorded force in each bar against the value calculated analytically. The LabVIEW software facilitates direct side-by-side comparison of measured and theoretical data.
Q3: How many truss configurations can be built with the FX-514?
Three distinct truss geometries can be constructed using the provided bar set. The six bar lengths — 150 mm, 259 mm, 300 mm, 397 mm, 424 mm, and 520 mm — in the quantities supplied allow bars to be combined at angles of 30°, 45°, 60°, and 90° to form different planar truss forms within the support frame. The node disc pin-install system allows configurations to be changed quickly between experiments.
Q4: What software is used with the FX-514, and what are its system requirements?
The FX-514 uses DAQ software developed specifically for this apparatus in the National Instruments LabVIEW environment. The software acquires data from all 12 strain gauge channels simultaneously, displays bar forces graphically in real time, and supports data recording and comparison against theoretical values. It includes a comprehensive help function and is compatible with any Windows operating system.
Q5: What is included in the scope of delivery for the FX-514?
The FX-514 is supplied as a complete experimental kit including: one set of bars (1 x 150 mm, 3 x 259 mm, 7 x 300 mm, 1 x 397 mm, 3 x 424 mm, 1 x 520 mm) each with integrated strain gauge load cell; 5 standard node discs; 2 support node discs; 1 load application device (−500 to +500 N, 0.01 N graduation); 1 set of measurement cables; DAQ software (LabVIEW-based, Windows compatible); and 1 instructional manual covering assembly, experimental procedures, and data analysis guidance.