Uniaxial strength of a composite array of overlaid and aligned prepreg platelets

17 Jul 2019 | Contributor(s): Sergey Kravchenko, Drew Sommer, Byron Pipes

The tensile strength of a discontinuous composite system consisting of aligned, unidirectional prepreg platelets is predicted by performing progressive damage analyses in a periodic representative volume element. Interlaminar and in-plane damage mechanisms are combined to...

US-COMP: Next Generation of Composites Materials for Crewed Deep Space Missions

15 Dec 2023 | Contributor(s): Greg Odegard

Current state-of-the-art composite materials are not light/strong enough for crewed missions to Mars and beyond. Structural components of deep space vehicles require lighter/stronger materials for fuel efficiency. The NASA Space Technologies Research Institute (STRI) for Ultra-Strong Composites...

Use of Digimat to Simulate Progressive Failure in a T-stiffener Accounting Voids Due to Manufacturing Defects

18 Apr 2016 | Contributor(s): Xuan Wang

Laminate T-stiffeners are widely used in the aerospace industry to transfer the 3D complex loads between the stiffener and theskins. However, the way they are manufactured can affect their inherent properties.In this case, we have considered that the stiffener and the skin were assembled using an...

VABS: Modeling Composite Beam-like Structures with 3D FEA Fidelity

06 Feb 2021 | Contributor(s): Wenbin Yu

This presentation was given at Altair Virtual ATCx Composites: https://atcxcomposites.virtual.altair.com/. Variational asymptotic beam section (VABS) is a unique technology continuously funded by the US Army since 1988 and it has become a tool of choice in the helicopter and wind turbine...

VABS: Powering Simple Beam Elements with Detailed 3D FEA Fidelity

06 Jan 2017 | Contributor(s): Wenbin Yu

This presentation gives a brief introduction to VABS, a general-purpose cross-sectional analysis, which can power conventional, simple beam elements with detailed 3D FEA fidelity. 

Variational asymptotic micromechanics modeling of heterogeneous piezoelectric materials

24 Jul 2017 | Contributor(s): Tian Tang, Wenbin Yu

In this paper, a new micromechanics model is developed to predict the effective propertiesand local fields of heterogeneous piezoelectric materials using the variational asymptoticmethod for unit cell homogenization (VAMUCH), a recently developed micromechanicsmodeling technique. Starting from...

Variational Asymptotic Modeling of Composite Dimensionally Reducible Structures

09 Nov 2014 | Publications | Contributor(s): Wenbin Yu

This is Prof. Yu's PhD dissertation. In this disseration, the variational asymptotic method has be used to provide a systematic, holistic, and rigorous approach to construct efficient yet accurate models for composite beams, plates, and shells.  

Variational Asymptotic Modeling of Composite Dimensionally Reducible Structures

23 Dec 2015 | Teaching Materials | Contributor(s): Wenbin Yu

Prof. Yu's PhD dissertation.

Viscoelastic Shear Lag

13 May 2013 | Tools | Contributor(s): Nicholas Smith

Simulate the creep and stress relaxation of a uni-directional short-fiber composite.

VUMAT of a Generalized Standard Continuum Damage Model

13 Apr 2018 | Downloads | Contributor(s): Zhenyuan Gao, Liang Zhang, Wenbin Yu

Based on a recently developed generalized standard continuum damage model (CDM), this VUMAT user subroutine provides a rigorous and robust framework for implementing various damage behavior into 2D or 3D solid elements in a finite element analysis (FEA). It is designed to be used with...

Windows Workspace

19 Aug 2015 | Tools | Contributor(s): Christopher J. Nuland, Hunter Martin, Andrew James Spiker

A sandbox environment for testing your Windows based tools

Woven fabrics UMAT- a coupled material model

01 Aug 2017 | Downloads | Contributor(s): Masoud Haghi Kashani, Masoud Hejazi, Abbas Hosseini, Farrokh Sassani, Frank Ko, Abbas S. Milani

One of the advantages of woven fabrics over unidirectional prepregs is their superior formability thanks to the large shear deformation capability. There exists, however, a limit on the shear deformation of woven fabrics, namely the wrinkling. Applying tension to delay wrinkling during forming...

Young Boeing

22 Jul 2013 | Online Presentations | Contributor(s): Johnathan Goodsell (editor), Jerry Young

Presentation at the May 2013 Composites Design and Manufacturing HUB workshop