GENOA by AlphaSTAR Webinar 2014 Series A Composite Software Solution

Overview
AlphaSTAR and the Altair Partner Alliance have teamed up to offer a monthly webinar focusing on various topics involving the GENOA and MCQ software solution suite.

Check back regularly as new topics and sessions are scheduled!

2/13/2014 Tension after Impact Recording 11 a.m. EST 3/13/2014 Effect on Fatigue Life Webinar 11 a.m. EST 4/10/2014 Multi Scale Progressive Failure Analysis Webinar 11 a.m. EST

Session Descriptions

Title: Tension after Impact: Damage Progression Coupling Different Structural FE Solvers in Sequence
Date: February 13th 2014
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Abstract
Join the webinar on February 13th 2014 for a discussion on how GENOA can be used to couple different analysis types together using different FE solvers so that advanced structures can be analyzed and assessed for damage initiation and propagation, fracture initiation and propagation using the engineering technology of choice.

Knowledge of the residual strength of a composite after a possible damage event is important. It allows the engineer to asses many ‘what-if’ situations in order to make a robust design.

Using GENOA, damage, residual stresses, and deformed/fractured meshes from one type of analysis type and solver can easily be used as the starting point for a completely different analysis and solver. This allows the residual strength of a structure to be computed based on a customized user defined life cycle for a structure all with users choice of technology.
An example will be shown that simulates impact with LS Dyna and then tension after impact using OptiStruct. Damage and residual stresses after impact and used to begin the tension after impact analysis.

We will also show our MULTI-SCALE methods carrying FE results down to the micro scale level so that the root damage mechanisms are assessed and the resulting degradation is accurately represented for every finite element and for every load step in the analysis.


Title: Effect of Voids, Defect Shapes and Sizes, and Fiber Waviness on Fatigue Life
Date: March 13th 2014
Time: 11 am EST
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Abstract
Join the webinar on March 13th 2014 for a discussion on how GENOA and MCQ can be used to determine the effect of voids, defect shapes and sizes, and fiber waviness on fatigue life. Using this methodology advanced structures can be analyzed and assessed for damage initiation and propagation, fracture initiation and propagation.

Knowledge of the life of a composite structure with defects is important since it reflects the “as-is” condition. It allows the engineer to assess many types of internal defects, their distribution, shapes, and size, in order to make decisions and produce a robust design.
An example will be shown that simulates these effects on an open hole tension coupon undergoing quasi static fatigue as well as random fatigue.

We show our MULTI-SCALE methods carrying FE results down to the micro scale level so that the root damage mechanisms are assessed and the resulting degradation is accurately represented for every finite element and for every load step in the analysis.


Title: 1D, 2D, and 3D, Unidirectional, Weave, and Braid Modeling and Reverse Engineering Constituent Properties for Use in Multi Scale Progressive Failure Analysis
Date: April 10th 2014
Time: 11 am EST
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Abstract
Join the webinar on April 10th 2014 for a discussion on how GENOA and MCQ can be used to determine the constituent properties – fiber, matrix, and stress strain curves for unidirectional composites. We will also discuss how to model weaves and braids. These 1D, 2D, 2.5D and 3D architectures can be used in FE solvers to assess for damage initiation and propagation, fracture initiation and propagation.

Material, damage, and fracture modeling is a very important step in finite elements. We will begin by discussing the material modeling for complex architecture and the damage and fracture criteria used to model progressive failure analysis.

An example will be shown that models 1D, 2D, and 3D architecture for a simple coupon and then uses that to perform a progressive failure analysis of an automotive vehicle component.

We show our MULTI-SCALE methods carrying FE results down to the micro scale level so that the root damage mechanisms are assessed and the resulting degradation is accurately represented for every finite element and for every load step in the analysis.

Webinar on GENOA Live Tutorial, July 18th 11AM EDT/Please Register

GENOA Live Tutorial

Evaluate Where, When and Why Failure Occurs in Composite Structural Components Using GENOA

Durability & Damage Tolerance (D&DT) of composite structural components is an important task that several aerospace, automotive and other industries have to go through to ensure reliability. Traditionally, analyses are performed using homogenized ply properties. The results, however, do not predict the test because of highly heterogeneous nature of the composite plies. GENOA D&DT Software package utilizes micro-mechanics while considering uncertainties including effect of defects based methodology and empowers commercial FE solvers with several in-built specialized capabilities. The focus of the software package is to help engineers minimize testing (small to large scale) without the loss in accuracy. Score of applications have been verified against several classes (glass, carbon, etc.,) of composites.

Join the web conference on July 18th 2013 for quick start tutorial on how to navigate in GENOA and perform D&DT analysis. The demonstration will center on the following:

1) Navigate in GENOA: In-built ASTM standard coupon, test validation cases, material library, etc.,
2) Test Validated Case Study: Composite structural components D&DT analysis; Importing/Editing FE models; output shows damage evolution up to final failure including a) matrix micro-cracks, b) fiber and matrix damage, c) delamination type initiation/growth, and d) contributing modes of damage.

7/18/2013 Register Now 11 a.m. EDT

Material Qualification and Certification Determine Allowables by Means of Virtual Simulation Combined With Limited Testing

Issue #16 - October 20th, 2008

Software Suite for Durability, Damage Tolerance, Reliability & Life Prediction
Enhances FEA Solvers MSC Nastran*, ABAQUS, ANSYS, RADIOSS & LS-DYNA

* Best Performance and Verified Solutions with MSC Nastran

This Week's Feature Composite Example

Material Qualification and Certification Determine Allowables by Means of Virtual Simulation Combined With Limited Testing

(a) Top View (laminate)  (b) Top View (individual plies) (c) Iso-View (laminate) (d) Iso-View (individual plies) Figure 1 - Virtual Testing of an Open-hole Coupon with Progressive Failure Analysis

A-basis and B-basis strength values are critical to reduce risk in structural design of composite aircraft structures. A previous newsletter presented a novel approach to determine A- and B-basis allowables for composite materials (click here for previous newsletter). This newsletter provides additional details of the A and B-basis allowable generation and describes a link between virtual testing and design carpet plots. 

The calculation of allowables for polymer matrix composite for aerospace applications is governed by FAA and Military Handbook 17-E standards and rules. The process is costly and time consuming as large numbers of coupon tests are inevitable (example: the generation of allowables for the IM7 fiber and 5250 resin for the F22 program cost close to 100 million dollars). To accelerate the prediction of allowables and reduce the number of coupon tests, GENOA combines multi-scale composite modeling with progressive failure analysis (PFA), probabilistic analysis and minimum test data to determine A- and B-basis values. Figure 1 shows the multi-scale PFA. The PFA is used to produce virtual scatter data using probabilistic analysis. Figure 2 shows the process flowchart. The scatter in material strength is determined by iterating on coefficient of variations (COV) of random variables from single or multiple sources of uncertainties (i.e. fundamental material properties and fabrication variables). The iterative process replicates scatter in the strength value obtained from the test of one coupon of each material batch. If the scatter is unknown, then maximum of 10% coefficient of variation can be chosen as per the FAA regulations for composite materials. However, when test data variation is known, then a COV can be estimated, as shown in Figures 3 and 4. In Figure 3, a COV of 0.06 provides a good estimate of the test data and in Figure 4, a COV of 0.01 is used. The methodology is applicable to notched (Figure 5) and un-notched coupons and structures and has the potential of reducing the coupon count for testing by over 60%. 

It is important to have design envelopes before and after the A- and B-Basis values are generated. The design envelop is a graphical representation of the variation in material properties (stiffness, Poisson's ratio, and strength) with variation in ply angle [e.g., 0/+45/-45/90] distribution in the laminate. The graphical representation is referred to as a 'Carpet Plot' in industrial practice. A typical Carpet Plot is shown in Figure 5. The carpet plot is a powerful tool which can be used as a design reference. In GENOA, a carpet plot is generated automatically after virtually simulating ASTM standard or other chosen testing methods (Figure 1). First, the layup in the laminate is automatically varied and ASTM or user defined tests are virtually simulated for each laminate layup. This is an automated process, requiring minimal user interface. Next, the virtual test database is filtered for the carpet plot information desired and plotted graphically.  The carpet plots generated need not be limited to A and B-basis allowables. Other carpet plot options include laminate stiffnesses, first ply failure and final failure. If test data is available, then test results can be plotted on top of the virtually generated carpet plots for verification.

More focus on virtual testing and carpet plot utilization to reduce physical test matrix reduction will be shown in upcoming future newsletters.

 

Figure 2 - Flowchart for generating A-basis and B-Basis Allowables in GENOA using testing standards for ASTM and MIL-HDBK 17-E and FAA

Figure 3 - Cumulative Density Functions (CDFs) with assumed coefficients of Variation of 0.06, 0.075, 0.10 for compressive composites un-notched composite coupon  [1]

 

Figure 4 - Scatter from test and simulation for the strength of the open-hole coupon along with GENOA predicted A- and B-Basis values [2]

 

Figure 5 - Carpet plot for various percent of 45 deg plies is useful to reduce coupon testing

References:

1. G. Abumeri, M. Garg, and M. R. Talagani, A Computational Approach for Predicting A- and B-Basis Allowables for Polymer Composites, SAMPE Fall Conference, TN, 2008.
Click here to email us for the technical publication.

2. M. R. Talagani, Z. Gurdal, and F. Abdi, S. Verhoef ?Obtaining A-basis and B-basis Allowable Values for Open-Hole Specimens Using Virtual testing? AIAAC-2007-127, 4. Ankara International Aerospace Conference, 10-12 September, 2007 ? METU, Ankara.
Click here to email us for the technical publication.

Click here to read the full technical product data sheet of GENOA.

This issue was brought to you by Alpha STAR Corporation.

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