BYU Structural Dynamics Research Group

Structural vibration is the key to engineering aircraft so that their wings and other structures can survive high speed flight, or spacecraft that can survive the shaky ride to space. It is also responsible for the noise you hear when driving down the freeway in a cheap car, or the quiet and smoothness of a luxury car. Our research group works at the boundary between experimental and analytical structural dynamics. Our current projects are involved with characterizing, modeling and testing nonlinear dynamic systems. We are also interested in novel systems such as micro- or nano-scale devices (e.g. devices measured in millionths or billionths of a meter) and also dynamic motion of the human body.

Past projects have focused on identifying models for dynamic systems from measured response data, on developing more robust methods for predicting the response of assemblies structures in the presence of uncertainties, and novel ways of using lasers to measure a structure’s response. A few past projects are highlighted below.

Virtual Lab Tour

This video gives a tour of our lab and discusses some of the projects that we work on.

For a high level introduction to structural dynamics, see Dr. Allen’s talk on WPTV on Structural Dynamics Challenges for Launch

Selected Research Highlights

National Science Foundation Funded Research: Models for Material Damping of Powders in Additively Manufactured Metal Parts (2024-2026)

Vibrations, or small motions of structures, can produce unwanted sound or noise and, in extreme cases, can cause a structure to fracture and fail. For example, the blades of jet engines sometimes break during operation, damaging the aircraft and potentially endangering lives. This grant will support research into a new way of designing and manufacturing parts so that they absorb much more vibration than existing metals. A relatively new manufacturing process, called additive manufacturing or 3D printing, has recently gained popularity for producing metal parts. Using this process, parts are created one layer at a time from a bed of metal powder by using a laser to melt and fuse the metal at certain locations. Any powder that is not fused is typically washed from the finished parts. This work proposes to design parts such that they retain pockets of trapped metal powder. These pockets can be designed to increase parts’ ability to absorb vibration, reducing stresses in the parts and the noise that they generate. The work includes both an experimental component and a modeling component. In the experimental component, various parts will be created and tested to understand what shapes produce the most vibration absorption and the conditions under which they absorb vibration. In the modeling component, the investigators will seek to understand the properties of the metal powders and to quantify them, so they can be included in computer models that predict the motion and vibration absorption of metal parts.
Overview of NSF Powder Damping Project

AFOSR Project on Substructuring for Nonlinear Systems

Allen was Awarded an AFOSR Young Investigator award to study nonlinear vibration of assemblies of subcomponents. The project aims to facilitate design of hypersonic vehicle skin panels. (click here to read press release)

Schematic Hypersonic Panel

National Science Foundation Funded Project on Linear Time Periodic Systems

Allen & Sracic create a new continuous-scan laser vibrometry method that can reduce test time by orders of magnitude (click on image below for more information).

Dr. Allen’s Doctoral Research on Structural Health Monitoring for a Highway Bridge

Impulse response of Swiss Highway Bridge (click on animation above for more information)