Theory Archives - ESRD

StressCheck Demo: Computing 2D and 3D Stress Concentrations for an Infinite Plate with Hole in Tension

brent — Wed, 24 May 2023 15:23:34 +0000

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Webinar: Benefits of Mixed Meshing for Multi-Body Contact Applications

brent — Mon, 13 Mar 2023 20:42:18 +0000

[vc_row][vc_column width="1/2"][vc_message message_box_color="peacoc" icon_fontawesome="fa fa-lightbulb-o"]March 13, 2023 @ 1:00 pm EST[/vc_message][vc_column_text]Strategies for incorporating advanced mixed (hexa/penta) automeshing techniques for improved quality and efficiency of 3D multi-body contact applications will be explored.[/vc_column_text][vc_cta h2="" add_button="right" btn_title="WATCH NOW" btn_color="danger" btn_link="url:%23recording|||"]This webinar is now available to watch on-demand.[/vc_cta][/vc_column][vc_column width="1/2"] [caption id="attachment_27442" align="alignnone" width="1166"] 3D Splice Plate problem definition (top right), mixed mesh taking advantage of symmetry (top left) and plate von Mises stresses (bottom).[/caption] [/vc_column][/vc_row][vc_row][vc_column][vc_column_text]

WEBINAR SUMMARY

[/vc_column_text][vc_custom_heading text="In this 3-part, pre-recorded 40-minute webinar we will present how the automeshing enhancements now available in StressCheck v11.1 significantly aid in the rapid generation of penta- and hexa-dominant meshes for use in 3D multi-body contact applications. To realize these concepts in a practical setting, a 3D splice joint assembly will be constructed, analyzed and post-processed, with detailed commentary on each step in the workflow process." font_container="tag:p|text_align:left" use_theme_fonts="yes"][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]

WEBINAR HIGHLIGHTS

[/vc_column_text][vc_column_text]Part 1: Model Definition & Parametric Geometry Construction

Problem definition, scope and use of symmetry to reduce model size
Importation of a parameter file (.par)
Construction of 3D parametric solid bodies (boxes, cylinders, cones, etc.)
Boolean union/subtraction operations between 3D solid bodies to define 3D splice joint parts
Copy operations to duplicate child fastener bodies from a single parent fastener body
Body-to-body imprints between all parts for optimization of contacting surfaces

Part 2: Part Definition, Contact Zone Setup, Mixed Mesh Generation, Material Properties & Boundary Conditions

Creation of Parts for efficient bookkeeping and visualization
Generation of the solid mixed meshes for each Part via Global, Boundary Layer and Thin Section automesh methods
Creation of contact zones for Part regions expected to be in contact
Definition and assignment of material properties to each Part
Assignment of boundary conditions (loads and constraints) to each Part
Assignment of contact pairs to allow gap and pressure computations between Part contact zones

Part 3: Solution Setup, Execution and Post-Processing

Linear multi-body contact solution setup and initiating the solver
Evaluation of max contact pressure error, solve time and degrees of freedom solved (DOF)
Plotting the deformation of the 3D splice joint assembly
Plotting of von Mises stresses for each Part in the 3D splice joint assembly
Unaveraged vs. averaged von Mises stresses for each plate Part
Computing the stress resultants to ensure quality load transfer between Parts
Summary and wrap-up

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StressCheck Demo: Thermo-Mechanical Analysis with Temperature-Dependent Material Properties

brent — Wed, 18 Jan 2023 19:10:09 +0000

Abstract: A thermo-mechanical (Heat Transfer -> Elasticity) analysis is performed for a Handbook model of two Inconel 718 connected pipes connected by a thin fin (\Handbook\Tutorial\ConnectedPipes.scw). The parametric Handbook model contains formula-based, temperature-dependent coefficients of thermal conductivity (when the theory is Heat Transfer) as well as formula-based, temperature-dependent linear isotropic material properties (when the theory is Elasticity). The goals of the thermo-mechanical analysis are to:

Compute the linear (coefficient of thermal conductivity for a reference temperature T=200 °F) and material nonlinear (coefficient of thermal conductivity is allowed to be temperature-dependent) temperature distributions via steady-state conduction heat transfer
Apply the temperature distribution computed from the material nonlinear solution as a thermal load for all elements using a reference temperature of 0 °F
Solve a linear elastic solution using the thermal load, symmetry/rigid body constraints, and temperature-dependent linear isotropic properties
Extract the local stresses at the intersection of the fin and the pipes.

For the steady-state conduction heat transfer analysis, the following boundary conditions are assigned:

Cooling of the external pipe surfaces is by convection via parameters "Hc" (convective film coefficient) and "Tc"(convective temperature).
The left pipe inside temperature is given by parameter "To", and the right pipe inside temperature is given by parameter "Tp".

For the linear elastic analysis, the following boundary conditions are assigned:

Thermal loading of the connecting pipes + fin is defined by importing the temperatures from the material nonlinear steady state conduction heat transfer solution.
Double-symmetry conditions are used to model 1/4 of the connecting pipes + fin.
A nodal constraint in the global X direction restricts rigid body translation.

ASIP 2022 Training – Best Practices for the Modeling and Analysis of Bonded Doubler Repairs

brent — Mon, 05 Dec 2022 15:01:02 +0000

Abstract: this 2-hour training course, originally presented at the ASIP 2022 conference in Phoenix, AZ, explored the following topics:

StressCheck’s FEA technology implementation enabling modeling of very thin domains, including adhesive layers with 3D-solid elements.
Best practices and guidelines for modeling and analyzing 3D bonded repair doubler variations (e.g. racetrack/rectangular, circular/elliptical, tapered, metallic, ply-by-ply, homogenized, etc.) for circular cutouts and grindouts.
Performing “what if?” logic-driven studies of a digital 3D bonded repair handbook solution via StressCheck API-powered Engineering Simulation App, in which user-defined input data is passed from Python or Excel VBA to StressCheck Professional to perform scripted “on-the-fly” model adjustments and repair-oriented computations.

StressCheck Tutorial: Multi-Body Contact Analysis of a Block and Half-Cylinder

brent — Wed, 21 Sep 2022 14:13:34 +0000

Abstract: indenter-style problem of a block and loaded half-cylinder in multi-body contact is analyzed. The following tips and best practices will be explored:

Optimization of geometric surfaces for efficient multi-body contact.
Creation of contact zones on optimized surfaces.
Selection of the appropriate contact constant based on configuration (area in contact, material properties, load magnitude, etc).
Cancellation of rigid body translations/rotations.
Multi-body contact solution setup.
Assessment of final gap for penetration.
Assessment of contact pressure gradient continuity.
Assessment of load transfer via stress resultant extraction.
Mesh refinement with mixed boundary layers to improve contact pressure gradient.

For more details, refer to Multi-Body Contact Overview and Numerical Simulation Series: Mechanical Contact.

ASIP 2021 Training – Standardization and Automation of DaDT Solutions via FEA-Based Sim Apps

brent — Wed, 15 Dec 2021 02:16:03 +0000

Abstract: this 4-hour training course, originally presented at the ASIP 2021 conference in Austin, TX, explored the following topics:

The construction of a custom digital DaDT handbook solution via StressCheck Professional, including the parametrization of model input data and the storage of application-specific results extractions (i.e. SIF’s).
An overview of CAE Handbook, including pre-existing digital DaDT handbook solutions and how custom digital DaDT handbook solution may be utilized in a friendly, fail-safe environment.
Performing “what if?” logic-driven studies of digital DaDT handbook solution via a StressCheck API-powered Sim App, in which user-defined input data is passed from Excel VBA to StressCheck Professional to perform scripted “on-the-fly” model adjustments and DaDT computations.

StressCheck Demo: Comparing Manual Mesh and Automesh Results for a 3D Stepped Specimen

brent — Fri, 19 Nov 2021 13:37:21 +0000

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Simulation Governance & Management Webinar Slides

brent — Tue, 07 Sep 2021 15:43:04 +0000

Advancements in predictive computational science make it possible to increase reliance of numerical simulation, necessitating fewer physical experiments for substantial savings in time and costs of product development projects. The first and perhaps the most challenging obstacle to full realization of the benefits of predictive computational science is a widespread misunderstanding of what numerical simulation is. Most managers and many individuals who present themselves as experts in numerical simulation confuse numerical simulation with “finite element modeling” or “numerical modeling“. Those are outdated concepts, responsible for much of the disappointing results that caused widespread loss of confidence in the usefulness and reliability of numerical simulation. Current simulation and data management practices will have to be revised in order to meet the technical requirements of predictive computational science. The presentation will focus on the central role of simulation governance and management in the coordination of experimental and analytical work necessary for proper use of the tools and techniques of predictive computational science with the objective to maximize the reliability of computed information. Watch the webinar here. Note: this webinar was originally prepared by Drs. Szabó and Actis for the NAFEMS World Congress 2021 session on Simulation Governance.

Webinar: Simulation Governance & Management

brent — Thu, 02 Sep 2021 20:02:03 +0000

[vc_row][vc_column width="1/2"][vc_message message_box_color="peacoc" icon_fontawesome=""]September 2, 2021 @ 1:00 pm EST[/vc_message][vc_column_text]This 15-minute recorded presentation was prepared for the NAFEMS World Congress (Salzburg, October 2021). It highlights the mission-oriented nature of simulation governance and presents an example of a model development project.[/vc_column_text][vc_cta h2="" add_button="right" btn_title="WATCH NOW" btn_color="danger" btn_link="url:%23recording|||"]This webinar is now available to watch on-demand.[/vc_cta][/vc_column][vc_column width="1/2"][vc_single_image image="22431" img_size="full" add_caption="yes" alignment="center"][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]

WEBINAR SUMMARY

[/vc_column_text][vc_column_text]The main ideas of, and the case for, simulation governance are easy to understand. The development and implementation of a plan for simulation governance is not at all easy, however, and requires careful consideration of the mission, and associated predictive model(s), at hand. In this pre-recorded webinar, ESRD Chairman Dr. Barna Szabó addresses some of the key issues of simulation governance, including how model development must adhere to the requirements of simulation governance in order to minimize risk and magnify reliability. Note: this webinar was originally prepared by Drs. Szabó and Actis for the NAFEMS World Congress 2021 session on Simulation Governance.[/vc_column_text][/vc_column][/vc_row][vc_row][vc_column][vc_column_text]

WEBINAR HIGHLIGHTS

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Why planning for simulation governance is mission-dependent
Application of the concepts and procedures of predictive computational science: Focus on model development
Example of a model development project: Prediction of the probability of fatigue failure of a metal part subjected to cyclic loading in the high cycle range
Why the open-ended nature of model development projects makes the exercise of simulation governance essential

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Methodology of model development in the applied sciences

brent — Wed, 30 Jun 2021 13:10:42 +0000

Abstract: The formulation and validation of mathematical models in the applied sciences are largely consistent with the methodology of scientific research programmes (MSRP), however an essential modification is necessary: The domain of calibration has to be defined. The ranking and systematic improvement of mathematical models based on objective criteria are described and illustrated by an example. The methodology outlined in this paper provides a framework for the evolutionary development of a large class of mathematical models.