טכניון מכון טכנולוגי לישראל
הטכניון מכון טכנולוגי לישראל - בית הספר ללימודי מוסמכים  
M.Sc Thesis
M.Sc StudentSiton Refael
SubjectApplication of Contact Mechanics to Load Sensing
DepartmentDepartment of Mechanical Engineering
Supervisor Professor Daniel Rittel
Full Thesis textFull thesis text - English Version


Abstract

In this thesis, we design and investigate a unique Load Cell - Contact Load Cell (A load cell based on contact mechanics theories).

A load cell is a transducer that is used to convert force into an electrical signal. Today most load cells comprise strain gages, but there are other types of load cells as well.

The original application of contact mechanics and basic electrical concepts were used to develop the load-sensing device. While practical advantages can be demonstrated for this kind of load-cells, the main purpose of the work is a systematic investigation of the cross correlation between contact mechanics concepts and load sensing applications.

When two elastic bodies are pressed together they establish a contact area. If the contacting bodies are maintained at different electrical potentials, an electrical current will flow between them and there will be a contact resistance associated with the constriction of the current through the contact area.

Based on literature review the analytical force-resistance model was derived. For the model proposed, the contact area was assumed to consist of a single elliptic contact area, which results from two compressed elliptical surface.

In order to validate the model, experiments were carried out. The experiments show a good correlation between the applied force and contact resistance and similar behavior as in theory but with some limitations, discussed throughout the thesis.