Session: 03-03-01: Damage, Fatigue, and Fracture I

Paper Number: 107146

107146 - Investigations on Natural Frequency Shifts of a Cantilever Beam With a Spherical Void Defect 

Additive manufacturing methods, specifically metal 3D printing techniques are being used to allow intricacies of design never-before possible with traditional machining methods. Nevertheless, while a great deal of research has investigated the characteristics of cracks and defects in traditionally manufactured parts, far less work has examined the dynamic signatures associated with defects common to metal 3D printed parts. This paper investigates the dynamic signatures correlated with internal ablations in an additively manufactured, metal, cantilever beam. A mathematical model is developed to define the second area moment of a rectangular cantilever beam in the presence of a spherical void. Through the direct integration method, an explicit solution for stiffness is determined for a defected beam. From this, the first natural frequency is approximated. Further, a two-dimensional finite element model of the cantilever beam is performed. Finally, a three-dimensional ANSYS modal and transient analysis are conducted to determine mode shapes and natural frequencies of a cantilever beam. Through the homogeneity of the derived method results, validity for the characterization of the dynamic signatures due to a spherical void may be achieved. Additional simulations of defected cantilever beams with internal microstructure common in additive manufacturing are also considered. The proposed approach outlined in this work may be used to inform future experimental testing procedures in metal additively manufactured parts.

Presenting Author: Jeremy West California State University Chico

Presenting Author Biography: Jeremy West is a Mechanical Engineering Undergraduate from Chico State graduating in May 2023. He plans to pursue a Masters in Mechanical Engineering with emphasis on vibrational analysis.

Authors:

Jeremy West California State University Chico
Trevor Folden California State University Chico
Dennis O'connor California State University Chico