Assignment 7.pdf - Assignment 7 Physical reliability models...

This preview shows page 1 - 2 out of 2 pages.

1 Assignment # 7: Physical reliability models 1. The time to failure of a drill bit is lognormal with s = 1.43. From field data the median life of the bit has been found to depend on the Brinell hardness and the density of the material being drilled. The following function was empirically derived: ( ) 2 1 35 . 0 0157 . 0 31 . 12 x x x u = where x 1 is the Brinell hardness and x 2 is the density (mg/m 3 ). If a steel plate has been heat-treated to a Brinell hardness of 200 and has a density of 7.3 mg/m 3 , determine its reliability over 20 cutting hours. 2. Consider the following load distribution: ( ) otherwise kg 1000 x 0 x x f x Ω Ψ Χ = 0 10 / 3 9 2 If the strength is a constant 950 kg, determine the static reliability. 3. The strength of a concrete structure designed to support a fixed load of 464 lb has the following probability density function: ( ) lb 1000 y 0 y y f y = 9 2 10 3 (a) Compute the static reliability. (b) If the load is also random having the probability density function below, find the static reliability. lb x x x f x 1000 0 ) 000001 . 0 001 . 0 ( 2 ) (
Image of page 1

Subscribe to view the full document.

Image of page 2
  • Three '17
  • Bouanar Jack

{[ snackBarMessage ]}

Get FREE access by uploading your study materials

Upload your study materials now and get free access to over 25 million documents.

Upload now for FREE access Or pay now for instant access
Christopher Reinemann
"Before using Course Hero my grade was at 78%. By the end of the semester my grade was at 90%. I could not have done it without all the class material I found."
— Christopher R., University of Rhode Island '15, Course Hero Intern

Ask a question for free

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern