Chapter 4.3, Problem 20P

Using the four-point bending tool, discuss how measurements of transverse strain using DIC and compare with those from the strain gauge attached at the centre top of the specimen. In your answer, include the following: a. A short explanation of how each of the strain measurement techniques works. (4 marks) b. A description of the methodology you have used to make the data that you discussed from each technique as comparable as possible. (6 marks) c. A set of figures (images, graphs and/or tables as necessary) with appropriate captions demonstrating the comparability of data extracted from the two strain measurement methods. This should include at least three different applied loads. (10 marks) d. A brief description of the findings. (5 marks)

An undamped single-degree-of-freedom system consists of a spring with stiffness k = 10 kip/in and a mass weighing W = 10 kips. The system is at rest and it is suddenly subjected to a half-cycle sine pulse force. The pulse force has an amplitude po = 1 kips and time duration td = 0.1 seconds. Calculate the maximum restoring force in the spring due to the pulse force.

m=400mm n=300mm q=28mm r=20mm P=0.9kN