Progressive Damage and Failure Analysis of Bonded Composite Joints at High Energy Dynamic Impacts

2019 ◽  
Author(s):  
AKHIL BHASIN ◽  
SURESH RAJU KESHAVANARAYANA ◽  
LUIS GOMEZ ◽  
ASWINI KONA RAVI ◽  
BRIAN P. JUSTUSSON ◽  
...  
Keyword(s):  
Failure Analysis ◽  
High Energy ◽  
Progressive Damage ◽  
Composite Joints ◽  
Damage And Failure ◽  
Bonded Composite ◽  
Dynamic Impacts

A RADIATION SENSITIVE ADHESIVE SYSTEM FOR FUNCTIONALLY GRADED COMPOSITE JOINTS

2021 ◽  
Author(s):  
SAMUEL B. HURVITZ ◽  
SCOTT STAPLETON ◽  
JAMAL HUSSEINI
Keyword(s):  
Adhesive Bond ◽  
Adhesive System ◽  
High Energy ◽  
Bond Line ◽  
Functionally Graded ◽  
Composite Joints ◽  
Stress Concentrations ◽  
Functionally Graded Composite ◽  
Bonded Composite ◽  
Radiation Sensitizer

Adhesively bonded composite joints can help reduce weight in structures and avoid material damage from fastener holes, but stress concentrations formed at the edges of the adhesive bond line are a main cause of failure. Stress concentrations within the adhesive can be reduced by lowering the stiffness at these edges and increasing the stiffness in the center of the joint. This may be achieved using a dual-cure adhesive system, where conventional curing is first used to bond a lap joint, after which high energy radiation is applied to the joint to induce additional crosslinking in specific regions. Anhydride-cured epoxy resins have been formulated to include a radiation sensitizer enabling the desired cure behavior. Tensile testing was performed on cured systems containing varying levels of radiation sensitizer in order to evaluate its effects on young’s modulus as a function of radiation dose.

Structures Technology for Component Damage and Failure Prediction

2021 ◽  
Author(s):  
Yuri Nikishkov ◽  
Gennadiy Nikishkov ◽  
Guillaume Seon ◽  
Brian Shonkwiler ◽  
Andrew Makeev ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Failure Modes ◽  
A Priori ◽  
Structural Features ◽  
Advanced Materials ◽  
Life Extension ◽  
Repeated Loading ◽  
Progressive Damage ◽  
Damage And Failure ◽  
Composite Tape

Advanced structural analysis methods, known as progressive damage and failure analysis tools, are being developed to predict initiation and propagation of damage under repeated loading based on capturing individual and interacting damage modes. This work shows the ability of the progressive damage and failure analysis method implemented in CDMat software developed at the University of Texas Arlington Advanced Materials and Structures Lab to predict strength and fatigue failure of an advanced mechanically fastened aerospace structural joint, the common feature test component (CFTC)—representative of flight-critical structural attributes and failure modes—without a priori knowledge of the test result. The CFTC structural features include a composite tape skin, a composite fabric stiffener, and an aluminum rib applying pull-through load through multiple countersunk bolts combined with the axial compression of skin and stiffener. Failure and damage predictions under static and constant-amplitude cyclic loading are compared with tests. Developed by Boeing under the Air Force Research Laboratory Composite Airframe Life Extension Program, the CFTC has been the most complex progressive damage and failure analysis validation article to date.

Benchmarking Mixed Mode Matrix Failure in Progressive Damage and Failure Analysis Methods

2018 ◽  
Author(s):  
FRANK LEONE ◽  
MADHAVADAS RAMNATH ◽  
IMRAN HYDER ◽  
STEVEN WANTHAL ◽  
JOSEPH SCHAEFER ◽  
...  
Keyword(s):  
Failure Analysis ◽  
Mixed Mode ◽  
Progressive Damage ◽  
Damage And Failure ◽  
Analysis Methods
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