Theory and Design for Mechanical Measurements
6th Edition
ISBN: 9781118881279
Author: Richard S. Figliola, Donald E. Beasley
Publisher: WILEY
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Chapter 11, Problem 11.20P
A strain gauge is mounted on a steel cantilever beam of rectangular cross section. The gauge is connected in a Wheatstone bridge; initially /?gauge = /?2 = ^3 = ^4 = 120Q. A gauge resistance change of 0.1 Q is measured for the loading condition and gauge orientation shown in Figure 11.24. If the gauge factor is 2.05 ± 1% (95%) estimate the strain. Suppose the uncertainty in each resistor value is 1% (95%). Estimate an uncertainty in the measured strain due to the uncertainties in the bridge resistances and gauge factor. Assume that the bridge operates in a null mode, which is detected by a galvanometer. Also assume reasonable values for other necessary uncertainties and parameters, such as input voltage or galvanometer sensitivity.
Figure 11.24 Loading for Problem 11.20.
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Chapter 11 Solutions
Theory and Design for Mechanical Measurements
Ch. 11 - Prob. 11.1PCh. 11 - 11.2 Calculate the change in length of a steel rod...Ch. 11 - 11.1 Calculate the change in length of a steel rod...Ch. 11 - 11.2 Calculate the change in length of a steel rod...Ch. 11 - 11.5 An electrical coil is made by winding copper...Ch. 11 - Compare the resistance of a volume of k X IO-2* m3...Ch. 11 - A conductor made of nickel (p, = 6.8 x 10-8 Q m)...Ch. 11 - Consider a Wheatstone bridge circuit that has all...Ch. 11 - 11.9 Consider a Wheatstone bridge circuit that has...Ch. 11 - 11.10 A resistance strain gauge with R = 120 Q and...
Ch. 11 - 11.11 A strain gauge that has a nominal resistance...Ch. 11 - Prob. 11.12PCh. 11 - 11.13 A single strain gauge is mounted as shown in...Ch. 11 - 11.14 A single strain gauge is mounted on a...Ch. 11 - 11.15 Equation 11.15 provides an expression for...Ch. 11 - 11.17 A steel beam member (vp = 0.3) is subjected...Ch. 11 - An axial strain gauge and a transverse strain...Ch. 11 - A strain gauge is mounted on a steel cantilever...Ch. 11 - Two strain gauges are mounted so that they sense...Ch. 11 - A rectangular bar is instrumented with strain...Ch. 11 - 11.23 A round member having a cross-sectional area...Ch. 11 - 11.24 A square structural member having a cross...Ch. 11 - 11.25 Show that the use of a dummy gauge together...Ch. 11 - Show that four strain gauges mounted to a shaft...Ch. 11 - 11.27 For each bridge configuration described...Ch. 11 -
Figure 11.25 Bridge arrangement for Problems...Ch. 11 - Prob. 11.29PCh. 11 - Prob. 11.30P
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