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

Structures and Materials Commons™

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

Articles 1 - 7 of 7

Full-Text Articles in Structures and Materials

Harnessing Extrinsic Dissipation To Enhance The Toughness Of Composites And Composite Joints: A State-Of-The-Art Review Of Recent Advances, Gilles Lubineau, Marco Alfano, Ran Tao, Ahmed Wagih, Arief Yudhanto, Xiaole Li, Khaled Almuhammadi, Mjed Hashem, Ping Hu, Hassan A. Mahmoud, Fatih Oz Dec 2024

Harnessing Extrinsic Dissipation To Enhance The Toughness Of Composites And Composite Joints: A State-Of-The-Art Review Of Recent Advances, Gilles Lubineau, Marco Alfano, Ran Tao, Ahmed Wagih, Arief Yudhanto, Xiaole Li, Khaled Almuhammadi, Mjed Hashem, Ping Hu, Hassan A. Mahmoud, Fatih Oz

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Interfaces play a critical role in modern structures, where integrating multiple materials and components is essential to achieve specific functions. Enhancing the mechanical performance of these interfaces, particularly their resistance to delamination, is essential to enable extremely lightweight designs and improve energy efficiency. Improving toughness (or increasing energy dissipation during delamination) has traditionally involved modifying materials to navigate the well-known strength-toughness trade-off. However, a more effective strategy involves promoting non-local or extrinsic energy dissipation. This approach encompasses complex degradation phenomena that extend beyond the crack tip, such as long-range bridging, crack fragmentation, and ligament formation. This work explores this innovative …


Cfrp Delamination Density Propagation Analysis By Magnetostriction Theory, Brandon Eugene Williams Dec 2023

Cfrp Delamination Density Propagation Analysis By Magnetostriction Theory, Brandon Eugene Williams

All Dissertations

While Carbon Fiber Reinforced Polymers (CFRPs) have exceptional mechanical properties concerning their overall weight, their failure profile in demanding high-stress environments raises reliability concerns in structural applications. Two crucial limiting factors in CFRP reliability are low-strain material degradation and low fracture toughness. Due to CFRP’s low strain degradation characteristics, a wide variety of interlaminar damage can be sustained without any appreciable change to the physical structure itself. This damage suffered by the energy transfer from high- stress levels appears in the form of microporosity, crazes, microcracks, and delamination in the matrix material before any severe laminate damage is observed. This …


Shape Optimization Of A Sandwich Composite Plate With Low-Velocity Impact Loading And Effect Of Finite Difference Sensitivity Analysis, Utsav Shah Aug 2021

Shape Optimization Of A Sandwich Composite Plate With Low-Velocity Impact Loading And Effect Of Finite Difference Sensitivity Analysis, Utsav Shah

Doctoral Dissertations and Master's Theses

The structural design of spacesuits is essential in an advancing future of both Lunar and Martian space exploration. A typical spacesuit is made of sandwich composite material and designed to withstand various pressure and loading conditions while also considering the safety and comfort of the astronauts. One of the critical load cases in spacesuit design is a low-velocity impact (LVI) which may occur due to tool drop and other similar scenarios. The objectives of this work were (a) to create a finite element (FE) model of a component of a spacesuit, (b) validation of the FE model through experiments, (c) …


Analysis Of After Impact Characteristics And Structural Optimization Of Cfrp Composite Plate, Zhennan He Dec 2020

Analysis Of After Impact Characteristics And Structural Optimization Of Cfrp Composite Plate, Zhennan He

Doctoral Dissertations and Master's Theses

Low-velocity impact (LVI) on composites may cause Barely Visible Impact Damage (BVID), which is one of the most common damage types and may result in a decrease in strength of the composite. The objectives of this research were (a) to identify the characteristics of a carbon/epoxy composite plate after low-velocity impact, (b) to create a validated model to simulate the impact process and progressive failure, and (c) to perform sizing and shape optimization of the laminate for improving the damage resistance of the plate. As a part of this thesis, composite plates were fabricated using carbon fiber reinforced polymer (CFRP) …


Laser-Based Interfacial Patterning Enables Toughening Of Cfrp/Epoxy Joints Through Bridging Of Adhesive Ligaments, Ran Tao, Xiaole Li, Arief Yudhanto, Marco Alfano, Gilles Lubineau Dec 2020

Laser-Based Interfacial Patterning Enables Toughening Of Cfrp/Epoxy Joints Through Bridging Of Adhesive Ligaments, Ran Tao, Xiaole Li, Arief Yudhanto, Marco Alfano, Gilles Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The ability to prevent catastrophic failures in secondary bonded CFRP adhesive joints is important for reliable automotive and aerospace structures. In a previous study, we proposed an innovative damage-tolerant interfacial design concept for adhesively bonded composite joints, which relied on the extrinsic dissipation of bridging adhesive ligaments enabled by controlling the adhesion at CFRP/epoxy interfaces. In this work, we experimentally validate this strategy by combining laser processing and mechanical testing using double cantilever beam (DCB) joints. Mechanical tests indicate that the pattern geometry, i.e., number and spacing of the areas with different adhesion, controls the formation of either single or …


On Controlling Interfacial Heterogeneity To Trigger Bridging In Secondary Bonded Composite Joints: An Efficient Strategy To Introduce Crack-Arrest Features, Ran Tao, Xiaole Li, Arief Yudhanto, Marco Alfano, Gilles Lubineau Mar 2020

On Controlling Interfacial Heterogeneity To Trigger Bridging In Secondary Bonded Composite Joints: An Efficient Strategy To Introduce Crack-Arrest Features, Ran Tao, Xiaole Li, Arief Yudhanto, Marco Alfano, Gilles Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Secondary adhesive bonding of carbon fiber-reinforced polymer laminates is of great interest for the aerospace and automotive industries. However, joint reliability is still a major concern because of fabrication-induced or service-related cracks that are difficult to monitor and can lead to catastrophic failure. In this work, we propose a patterning strategy where the careful design of spatially varying interface properties enables the formation of an adhesive ligament that acts as a crack-arrest feature. Bi-dimensional finite element models of adhesively bonded double cantilever beams were employed to investigate the role of the main parameters of the pattern (i.e., geometrical parameters and …


Real-Time Electrical Impedance Monitoring Of Carbon Fiber-Reinforced Polymer Laminates Undergoing Quasi-Static Indentation, Khaled Almuhammadi, Arief Yudhanto, Gilles Lubineau Jan 2019

Real-Time Electrical Impedance Monitoring Of Carbon Fiber-Reinforced Polymer Laminates Undergoing Quasi-Static Indentation, Khaled Almuhammadi, Arief Yudhanto, Gilles Lubineau

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laminated composites are vulnerable to damage from out-of-plane loading, particularly impact loading, and the incurred damage is often only detected by evaluating the post-impact condition of the composites. Real-time monitoring techniques are desirable for early detection of damage. Utilizing changes in the electrical properties of composites to track incurred damage is promising, but the interpretation of such measurements is still challenging. Here, an electro-mechanical system is introduced to understand how well we could detect mechanical degradation in carbon-fiber-reinforced polymer (CFRP) plates undergoing a quasi-static indentation (QSI) test, which is representative of an impact load. The system measures the in situ, …