EMA 611 Advanced Mechanical Testing
University of Wisconsin
Rod Lakes
Assignments.


Turn in assignments in the lab one week after they are assigned.

23 Jan. Revisit the derivation of stress = My/I for bending. It is assumed the material is homogeneous, isotropic, linear, elastic. Consider separately materials which are heterogeneous, anisotropic, nonlinear, or viscoelastic. Is the formula still valid? Point to specific steps in the derivation in your answer.

30 Jan. Calculate Young's modulus E for wood based on your preliminary lab data. This is a milestone for Lab 1.

6 Feb. Plot data taken in class on a log-log scale. Find the slope of each curve on the log-log scale. Interpretation will be discussed in class.

13 Feb. Determine the number of bits n for the analog-digital converters in the test frames in 1313 EH. Consider 2ⁿ = N in which N is the number of discrete levels in your data. Use your data for a compliant specimen such as the coffee stirrer. Recall that the frame is capable of 10,000 pounds in tension and 10,000 pounds in compression.
Determine a Young's modulus for a material tested in Lab 2 or 3; compare with accepted value. This is a milestone for Lab 2, 3.

20 Feb. Data were taken in a demonstration of sine wave response of 1 MHz ultrasonic transducers. Plot these data on a log - log scale. Explain the behavior briefly. Why are the transducers designed in this way?

27 Feb. Explain briefly what you think will happen if the slab buckling demonstration were done under load control rather than displacement control. Sketch a force displacement curve as part of your explanation.

If you have competed the report for servo hydraulic, replot the relaxation curve in the context of the definition of relaxation. Keep in mind zero time and pertinent units. If you have completed the report for ultrasound, determine attenuation from a curve fit of amplitude vs. distance; determine tan delta from attenuation. For all, make constructive suggestions on course improvements.

For group project, write a preliminary proposal on what you plan to do; one page per group.

(i) For group project, write a brief update proposal for your project including progress in the last week; one page per group.
(ii) If the fundamental torsion frequency of the 6061 alloy cylinder is 83.5 kHz,the length and diameter are 19 mm, and the mass is 14.558 g, find the shear modulus. What is Young's modulus if Poisson's ratio is 0.33? Suppose your wood beam from lab 1 has Young's modulus 10 GPa. How much will it bend at the end (in microns) if a 5 gram mass is placed at the end in cantilever bending?