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SIMULIA's picture

Coupled Euler Lagrangian Approach Using Abaqus/Explicit in the Bird Strike Aircraft Damage Analysis

Bird impact damage in complex aircraft structure has been investigated using explicit transient dynamic analysis by Abaqus/Explicit in order to fully employ its large library of elements, material models and the ability of implementing user defined materials. The numerical procedure has been applied on the very detailed large airplane secondary structure consisting of sandwich, composite and metallic structural items that have been modeled with 3D, shell and continuum shell elements, coupled with appropriate kinematic constraints.

SIMULIA's picture

Analysis of Innovative Composite Aircraft Structures

Innovative composite structures are increasingly being used in the aircraft industry. A critical point of these new composite parts is the attachment to the surrounding aircraft structure. In cooperation between different EADS Business Units, a new advanced composite load introduction rib is developed to minimize weight and manufacturing costs. The new design of the flap focuses on the load introduction rib and drive fitting including the integrated lugs for the attachment to the flap support structure.

SIMULIA's picture

Advanced Finite Element Analysis for the Skyhook- Boeing HLV Aircraft

Boeing and Skyhook International entered into an agreement whereby Boeing will design and build two prototypes of the new Skyhook HLV aircraft. This hybrid airship is intended to carry 40 tons of cargo 100 miles. Due to the flexible, non-linear nature of fabric airship envelopes, as well as the complexity of designing a hybrid airship, the internal loads model for this aircraft is being developed in Abaqus and will be solved non-linearly.

***ERROR: Bad Material definition: Zero or negative initial dilatational modulus caused by bad material data. Please check your.



I'm conducting hypoplastic VUMAT model in abaqus. It always has the following problem. 

***ERROR: Bad Material definition in element number 1: zero or negative
initial dilatational modulus caused by bad material data. Please
check your material input and any initial conditions if necessary.

hossein_r's picture

How to create a threaded bolt in Abaqus or ansys

Hi everone

I want to molel an implant. I want to create a bolt in Ansys or abaqus. but I cant create its threades. can you help me ?


IOSO Optimization Presentation Video Shots

Dear Colleagues,

We are going to demonstrate the possibilities of IOSO Design Optimization Software. Very quick video shots. Just take a glance at it.


Optimization of 3D serpentine cooling passage in turbine blade. 42 design
variables in total.

Abaqus: How to lower the stiffness linear curve of load vs deflection of concrete slab

Dear all,

Iam modelling a simply supported RC slab with Abaqus using Concrete Damaged Plasticity subjected to a concentrated load at the top surface of the slab. I have used element type C3D8R for concrete and truss elements to represent steel bars.


I found the result of FEM showed that the linear part of load versus deflection, i.e. from zero load up to yield load shows a very stiff curve compare to the experimental test results.


Methodology of simulation post-processing for metal parts in Abaqus

I mesh most of my parts in C3D8R. My simulation are quasi-static, and involve a lot of contacts. To model steel, I use a classic elastic-plastic behavior, coming from stress-strain curves we measured. I have the yield strength of the material and the strain at break. My questions concern post-processing.

Hot embossing in ANSYS

dear all,


Finally i found out the way to simulate PMMA embossing using Mooney Revlin constants at several tempature. Now i am trying to include Prony model and shift function with Hyperelastic model in ansys. I tried using static and transient analysis but it is not giving viscoelastic flow behaviour. If anyone done this kind of simulation in Ansys please help me. I am sending mooney revlin and prony model constants in ansys WB.

 To be included in command file.. 



Variables definition in Abaqus


I am working on a 3D contact problem where a spherical part is pressed against another spherical surface. I was wondering what variables may be interesting to study for this problem. I decided to look at the contact area CAREA, the contact pressure CPRESS and the stress S but I am not able to find how Abaqus defines and calculates these variables, does anyone know?


about using hashin criteria in abaqus

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Dear all, Hi

An Introduction to ATOM: Nonlinear Structural Optimization for Improved, Rapid Product Design (FREE WEBINAR)

Register for this FREE webinar to learn how the Abaqus Topology Optimization Module (ATOM), from Dassault Systemes SIMULIA, delivers advanced capabilities for nonlinear structural optimization and provides important benefits to engineers and product designers by identifying the optimized topology and shape of a structure.

For more information, visit:, or -> events -> webinars.

How to achieve creep crack growth in the ABAQUS

Recently, I have worked on the creep crack growth coupled with CDM. In the references, it says that when the element reached to the critical damage, the E of the element was reduced to 0. However, when I used this method in my UMAT, it can achieved creep crack growth in some elements. As the number of damaged elements increases, the damaged eelments distorted too large,as shown in attachment. Therefore, the calculation is stoped.

Does anyone know how to resolove this problem.


HussamNasreddin's picture

Plain concrete failure

Hello all,


I am trying to model concrete as an elastic material in ABAQUS. The model can be any simple structure (cube, beam or column) but the main feature is that concrete behaviour is elastic up to a limiting strain (St. Venant's theory). Which of the  Failure criteria in ABAQUS i should be using (Elasticity or brittle cracking)? if neither would you mind explaining other options?





New release now available for the Mimics Innovation Suite

Leuven,Belgium, May 31, 2011. Materialise is proud to announce the newest release of the Mimics Innovation Suite. The software solution, already renowned for being the fastest  and easiest method for getting accurate 3D surface models from imaging data, is now faster and more user-friendly than ever. An example of the improved features is that several

nonuniform load in abaqus


Iwant to know if there is any other way except user subroutine for applying nonuniform load in a 2 dimesional abaqus model.


How to simulate compaction process of powder mettalurgy in Abaqus?

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I am doing ph.d work related to powder mettalurgy 

I want to simulate the compaction process ( in powder mettalurgy) by using ABAQUS.It is very essential to find a way to create a model which will behave as such as PM part.

Simple Cell Traction Force Script for Elastic Micropatterned Substrata

Hi readers, 

 This is MATLAB code that was written by myself and collaborators that we've sought to make available to the wider research community. The program is intended to track the displacements of micropatterned dots on a substrate in a similar manner to that performed by  Maloney et al. in "Influence of Finite Thickness on cellular adhesion-induced deformation of an compliant substrata". Physical Review E. 2008.

sweep mesh of a dome in ANSYS

I am dealing with a partial sphere dome in ANSYS, I created the volume by extruding half of an arch area along the axis at the dome center. I am using SOLID65 elements. The problem I am facing now is how to properly sweep mesh the whole volume ( actually, there are four 90 degree partial sphere together after the extrude of the area), because if I simply sweep the volume, the elements around the top center of the sphere will cause element shape warning in the static analysis.

Dose anyone have any idea about how to deal with the mesh around the center? 

Looking for detail process for creating aircraft wing with given airfoil co-ordinate using CATIA V5 R18 Software



 I am looking for detail process to create aircraft wing with given airfoil co-ordinate(*.txt) file using CATIA V5 R18 software. If anyone know then please email me your method.


 Thanks in advance. 

  Bhavin Patel



Output of ABAQUS for contact of a rigid surface with a poroelastic layer

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Hello, I am modeling the spherical indentation of a poroelastic layer. I am modeling the indenter as a rigid analytical surface. As you know, the total pressure in a porous medium at each point is the sum of the elastic stresses from the matrix, and the pore pressure caused by fluid pressurization. Abaqus provides both the pore pressure and of course the rest of the stress quantities.


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