Composite Materials & Structures

The Engineering Mechanics and Composites (EMC) Research Laboratory is located on the third floor of the Engineering and Material Science Building of the University of Wisconsin-Milwaukee campus. As part of the Center of Advanced Materials Manufacturing...

[emcuwm]

Our book has been published.  Read more about it here:

PRESENTS THE LATEST STRATEGIES IN THE DEVELOPMENT AND USE OF COMPOSITE MATERIALS FOR LARGE STRUCTURES AND THE EFFECTS OF DEFECTS

Composite Structures: Effects of Defects  offers an important guide to the use of fiber-reinforced composites and how defects can affect the durability and safety of engineering structures such as aircraft, bridges, wind turbines and sporting equipment. The text draws on the authors’ experience in industry and academia to cover the most recent strategies in the development of composite structures and uniquely integrates the assessment of the effects of defects introduced during production and service.

This comprehensive resource begins with an essential introduction to the characteristics of composites leading to an in-depth discussion of defects encountered in production. The authors review current manufacturing methods and inspection techniques used for composite structures and methods to test and analyze their strength and behavior in the presence of manufacturing flaws and service impacts. The text also contains information on the latest regulatory requirements and design standards associated with the testing and validation of a robust design. This important resource:

Presents basic information on composite structural design and failure theories

Reviews the most current manufacturing methods and inspection technologies

Includes testing strategies for determining the effects of production defects and service damage

Contains methods for statistical analysis and processing of experimental effects of defects test data

Offers a comprehensive review of the most current regulatory developments in the use of composites for the construction of aircraft composite structures

Written for professional engineers in mechanical, automotive, aerospace, civil, and energy engineering, Composite Structures: Effects of Defects is the hands-on text that covers the essential information needed to understand the use of composites and how manufacturing flaws and service damage impact structural behavior.

[emcuwm]

EMCR Lab alumnus, Peng Yang has completed his MS degree at UW-Milwaukee.  Peng has worked in the lab as both an undergraduate and graduate researcher.  His MS thesis was titled, “Phase Sensitive Thermography of Magnetostrictive Materials Under Periodic Excitations.” His thesis was co-advised by Dr. Rani Elhajjar and Dr. Chiu Tau Law.  For more information about Peng Yang’s activities and to contact him directly, he can be found at https://www.linkedin.com/in/peng-yang-1b89ba42

[emcuwm]

Effects of resin pocket on compression failure in carbon fiber composites.

[emcuwm]

Sadegh Shams, researcher at the EMCRL has successfully defended his PhD thesis at the University of Wisconsin-Milwaukee.  The title of his thesis is, “Experimental, analytical and numerical characterization of effects of fiber waviness defects in laminated composites “

[emcuwm]

Peng Yang’s poster at @UWM on Phase sensitive thermography for detection of magnetostrictive strains

[emcuwm]

Aleksey Yermakov’s work on magnetostrictive composite sensors with 3D printing at 2016 #UWM poster competition.

[emcuwm]

Class photo with my students from the Advanced Topics in Experimental Stress Analysis course at the University of Trento in Italy as part of @FulbrightPrgrm

[emcuwm]

A new method is proposed to determine the onset of material failure in composite materials containing defects tested in tension. The new method is proposed since the load versus axial deformation...

[emcuwm]

Group photo - December 2015

Zhihua Ning, Andy Thompson, Peng Yang, Hamid Erfanian, Sadegh Shams, Tasha Graciano, Ed Lynch, Aleksey Yermakov, Rani Elhajjar

[emcuwm]

X-HAB Class of 2014-15 at final presentation May 21, 2015 at the Marshall Space Flight Center in Huntsville, Alabama.  From the left: Brandon Hitter, Rani Elhajjar, Quincy Bean, Patrick Severson, Mallory Johnston, Kelly Scott, Tressa Norden, Alex Francis, Bryan Sinkovec, Brent Erlauer, Justin Jarmuz, Jon Wolgamott, Nikki Przybyla, Aleksey Yermakov, Anthony Demuse and Alexandra Slay. 

[emcuwm]

Digital Edition

Feature article on X-Hab project in SAE Horizon magazine.

[emcuwm]

Publication on detecting fiber waviness using TSA method.

Elhajjar, R., Haj-Ali, R. and Wei, B., “An Infrared Thermoelastic Stress Analysis Investigation for Detecting Fiber Waviness in Composite Structures,” Polymer-Plastics Technology and Engineering, 53: 1251–1258, 2014

A full-field thermoelastic stress analysis infrared (TSA-IR) method is used to investigate the possibility of inspecting for out of plane fiber waviness in composite structures. Two different waviness profiles are generated and compared to control specimen having no anomalies. Tension and compression loading schemes are investigated and the TSA-IR emissions are compared to cross-sectional investigations. A subset of the specimens is also notched to investigate the thermal emissions from holes when compared to the waviness. The interaction of the hole and waviness shows the errors that can be introduced when using TSA-IR for quantitative analysis.

[emcuwm]

NASA’s X-Hab Academic Innovation Challenge

UWM is one of five universities invited to partake in the 2014-15 NASA sponsored X-HAB Academic Innovation Challenge. Civil Engineering associate professor R...

Nice Progress video from UWM Media Team on X-Hab class.

[emcuwm]

Compression testing of continuous fiber reinforced polymer composites with out-of-plane fiber waviness and circular notches

Abstract

ABSTRACT: We investigated the face-stabilized Open-Hole Compression (OHC) test method for evaluating the effects of fiber waviness on the compression strength of continuous carbon fiber reinforced polymer composites. Temporal evaluations of the load-deformation response, acoustic emissions and optical microscopy are used to understand the failure modes and damage progression in the OHC specimen. The failure modes observed are structurally correlated to matrix failure and kink zone formation leading to fiber fracture. The results show how the resin pocket plays a more critical role than the layup in influencing the initiation of damage in the composite specimens.

[emcuwm]

Dr. Elhajjar co-edits book 'Smart Composites-Mechanics and Design'

[emcuwm]

Student researchers from the Engineering Mechanics and Composites Lab participate in the NASA sponsored RASC-AL Lunar Wheel Competition.   Peng Yang and Stacy Van Dyke developed carbon-fiber/epoxy composite disk springs for the hybrid metal/composite wheels.  The wheels were mounted on a John Deere Gator utility vehicle and underwent field tests at NASA Johnson Space Center's Rock Yard in Houston, Texas (July 2013). 

[emcuwm]

3D full field strain analysis of polymerization shrinkage in a dental composite

June 13, 2013:  Authors:  Michael Martinsen, Rani F. El-Hajjar, David W. Berzins

Understanding the local deformations and strain fields from the initial polymerization shrinkage in dental composites can lead to a better understanding of the composite material and interaction with surrounding tooth structure, aiding in their further development and clinical prognosis.