# Civil Engineering

## A fatigue test was conducted in which the mean stress was 50 MPa (7252 psi), and the stress amplitude was 210 MPa (30460 psi).

A fatigue test was conducted in which the mean stress was 50 MPa (7252 psi), and the stress amplitude was 210 MPa (30460 psi). a) Compute the maximum stress level in MPa.b) Compute the minimum stress level in MPa.c) Compute the stress ratio.d)Compute the magnitude of the stress range in MPa. EXPERT ANSWER

## A cylindrical 4340 steel bar is subjected to reversed rotating-bending stress cycling, which yielded the test results presented in Figure 8.20. If the maximum applied load is 5000 N, compute the minimum allowable bar diameter to ensure that fatigue failure will not occur. Assume a factor of safety of 2.25 and that the distance between load-bearing points is 55.0 mm. Use the following relation between the stress () and the load (F)   16FL , (d0) is the cylinder  d 03 diameter, and (L) is the distance.

A cylindrical 4340 steel bar is subjected to reversed rotating-bending stress cycling, which yielded the test results presented in Figure 8.20. If the maximum applied load is 5000 N, compute the minimum allowable bar diameter to ensure that fatigue failure will not occur. Assume a factor of safety of 2.25 and that the distance between …

## We learnt in class that Torricelli measured the atmospheric pressure (Patm = 101 kPa) using a barometer, which he found to be equivalent to the hydrostatic pressure created by 76 cm of Hg (i.e., mercury). This way of recording pressure is still being used today. For example, blood pressure is usually given as the ratio of the maximum (systolic pressure) to the minimum pressure (diastolic pressure). A typical value for this ratio for a human is 120/70, where the pressures are in mm Hg. What would these pressures be in pascals? Please write your answer using the table method.

We learnt in class that Torricelli measured the atmospheric pressure (Patm = 101 kPa) using a barometer, which he found to be equivalent to the hydrostatic pressure created by 76 cm of Hg (i.e., mercury). This way of recording pressure is still being used today. For example, blood pressure is usually given as the ratio …