טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentSha'eir Or'el
SubjectAnalysis of Stress Concentration around a Hole with
Uncertain Shape, Based on Info-Gap Theory
DepartmentDepartment of Mechanical Engineering
Supervisor Professor Yakov Ben-Haim
Full Thesis text - in Hebrew Full thesis text - Hebrew Version


Abstract

Many mechanical systems are modeled as having a hole in an infinite elastic thin plate under uniform radial tension at infinity. In realistic situations we don't know the shape of the hole exactly because of human or machine errors, loading history, wear, etc. Info-gap theory is a methodology for supporting model-based design and maintenance decisions under severe uncertainty.

Surfacing-processing of the inner face of the hole can reduce sharp shape irregularities and thus reduce stress concentration. On the other hand, surface processing can also introduce systematic shape deviation from the nominal design shape, which can introduce stress concentration. The designer faces a dilemma which is strongly influenced by shape uncertainty.

This lecture will analyze the robustness of the plate to uncertainty in the shape of the hole, under uniform radial tension at infinity in an infinite elastic thin plate. We will employ the concept of an innovation dilemma to illustrate the surface-processing dilemma and other typical decision dilemmas. The info-gap robustness will be used to resolve the dilemma, prioritize the available alternatives, and reach a decision.