Open Access. Powered by Scholars. Published by Universities.®

Mechanical Engineering Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 3 of 3

Full-Text Articles in Mechanical Engineering

Solder Joint Design Optimization Of Quad-Flat Package With Gullwing Leads Under Accelerated Thermal Cycling And Power Cycling, Pranav Nikam May 2018

Solder Joint Design Optimization Of Quad-Flat Package With Gullwing Leads Under Accelerated Thermal Cycling And Power Cycling, Pranav Nikam

Mechanical and Aerospace Engineering Theses

Ever growing complexity in designing of Integrated Circuits and accommodating high number of Interconnections in the device is the main source of motivation in today’s world of IC devices. Quad Flat Package (QFP) with Gullwing leads is spearhead technology which enables high connectivity levels required to be customized in most convenient and advantageous form. Gullwing leads have the advantage of having a large area in contact with solder and also work as mechanical springs. They also make it easier to inspect and rework. Lot of work has been carried out on inspecting the reliability of solder joints in QFP packages …


Modeling Disk Cracks In Rotors By Utilizing Speed Dependent Eccentricity, Andrew L. Gyekenyesi, Jerzy T. Sawicki, Wayne C. Haase Oct 2012

Modeling Disk Cracks In Rotors By Utilizing Speed Dependent Eccentricity, Andrew L. Gyekenyesi, Jerzy T. Sawicki, Wayne C. Haase

Jerzy T. Sawicki

This paper discusses the feasibility of vibration-based structural health monitoring for detecting disk cracks in rotor systems. The approach of interest assumes that a crack located on a rotating disk causes a minute change in the system’s center of mass due to the centrifugal force induced opening of the crack. The center of mass shift is expected to reveal itself in the vibration vector (i.e., whirl response; plotted as amplitude and phase versus speed) gathered during a spin-up and/or spin-down test. Here, analysis is accomplished by modeling a Jeffcott rotor that is characterized by analytical, numerical, and experimental data. The …


Modeling Disk Cracks In Rotors By Utilizing Speed Dependent Eccentricity, Andrew L. Gyekenyesi, Jerzy T. Sawicki, Wayne C. Haase Mar 2010

Modeling Disk Cracks In Rotors By Utilizing Speed Dependent Eccentricity, Andrew L. Gyekenyesi, Jerzy T. Sawicki, Wayne C. Haase

Mechanical Engineering Faculty Publications

This paper discusses the feasibility of vibration-based structural health monitoring for detecting disk cracks in rotor systems. The approach of interest assumes that a crack located on a rotating disk causes a minute change in the system’s center of mass due to the centrifugal force induced opening of the crack. The center of mass shift is expected to reveal itself in the vibration vector (i.e., whirl response; plotted as amplitude and phase versus speed) gathered during a spin-up and/or spin-down test. Here, analysis is accomplished by modeling a Jeffcott rotor that is characterized by analytical, numerical, and experimental data. The …