SUBROUTINE
Laser forming simulation tutorial in Abaqus
The laser forming process is performed by applying thermal stresses to the workpiece surface by heating the surface with a laser beam. These internal stresses induce plastic strains in the part resulting in local elastic-plastic deformation (Laser-induced plastic deformation). In this laser forming simulation tutorial the DFLUX subroutine is used to apply heat flux (Gaussian heat distribution) dependent on location and time in finite element simulation. For example, the linear heating processes of laser forming and welding (with a slight simplification) can be simulated by this subroutine. In the linear heating process, by applying heat flux to the surface of a sheet, a thermal gradient is created in its thickness. This thermal gradient causes permanent deformation of the sheet. To simulate the laser forming process, it is necessary to apply a time and location-dependent heat flux to the sheet. In this type of loading, a heat flux is applied on the plate, which is defined using the DFLUX subroutine, including the laser power, movement speed, beam diameter, absorption coefficient, and laser movement path according to the designed experiments (Laser forming process parameters). To verify this Abaqus laser forming simulation, the simulation results and experimental results of sheet deformation (U) are compared. The displacement of the sheet in the simulation is in good agreement with the experimental results.
Short fiber composite damage (Mean Field Homogenization Model)
Short-fiber reinforced thermoplastics, popular due to their strength, lightness, and cost-effectiveness, are often manufactured using injection molding to create complex parts with dispersed short fibers. However, failure in these materials is complex, involving mechanisms like fiber cracking and plastic deformation. Current models for damage and failure are either macroscopic or simplified.
A new method tackles this challenge by evaluating stiffness using continuum damage mechanics with a multistep homogenization approach. This new method is called “Mean Field Homogenization”. This approach involves a two-stage process: first, the fibers are split into groups (grains). Then, mean-field homogenization is employed within Abaqus using a UMAT subroutine to average stiffness across these phases, followed by overall homogenization. This use of mean-field homogenization Abaqus simplifies the modeling of the composite's intricate geometry.
The method was validated through testing on a distal radius plate. Calibration was achieved through experiments, and the simulation was performed using Abaqus finite element software. It's important to note that the Abaqus short fiber damage mean field homogenization process was implemented within Abaqus through the INP code.
Tread wear simulation in Abaqus
This training package provides a comprehensive exploration of tire tread wear, focusing on its simulation using the UMESHMOTION subroutine in ABAQUS. Tread wear, the gradual erosion of a tire's outer rubber surface, impacts crucial performance aspects like traction and handling. The package elucidates the importance of tread wear simulation, emphasizing safety, performance optimization, regulatory compliance, durability, cost efficiency, environmental impact, and consumer confidence.
The UMESHMOTION subroutine, a key element in ABAQUS, is demystified through illustrative examples. Its application in modeling wear processes, specifically employing the Archard model, is highlighted—particularly in node movement specification during adaptive meshing.
The workshop within this package delves into simulating tire wear at a speed of 32 km/h over 1000 hours, utilizing the UMESHMOTION subroutine and Archard equations. The tire modeling process, transitioning from axisymmetric to three-dimensional elements, is detailed, considering both slip and non-slip modes of movement.
This resource serves as a valuable guide for professionals and enthusiasts seeking to understand and implement effective tread wear simulation techniques using advanced computational tools.
Hydroforming process simulation using VDLOAD subroutine in Abaqus
Dive into the intricacies of hydroforming simulation in Abaqus alongside the VDLOAD subroutine with our comprehensive guide. This tutorial delves into the essence of the Abaqus hydroforming simulation, unraveling the nuances of the hydroforming process simulation. Hydroforming, a specialized metal shaping technique applicable to diverse materials like steel, copper, and aluminum, is explored in depth.
In the workshop component, we specifically focus on advanced hydroforming simulation using the VDLOAD subroutine, highlighting its pivotal role in specifying fluid pressure on sheet metal forming. Learn how to apply the Functional Fluid Pressure Loading feature for precise control over fluid pressure dynamics. Additionally, explore the Smooth Amplitude option for defining part displacement seamlessly, without introducing dynamic changes during problem-solving.
Conclude your exploration with a comparative analysis of simulation outcomes, dissecting scenarios with and without fluid pressure using Abaqus hydroforming simulation. Engage in discussions on subroutine writing, delving into the intricacies of incorporating Fluid Pressure Loading into your simulations. This guide offers a natural progression through hydroforming and VDLOAD, providing valuable insights for efficient and accurate simulations.
Curing process simulation in Abaqus
Fiber-reinforced composites have found widespread use across various fields due to their remarkable properties. This necessitates a careful design of their manufacturing processes to attain industrial application quality. The critical factor influencing their quality is the curing process, wherein the resin transforms into a solid state under temperature cycles. However, the challenge lies in achieving optimal curing quality while maintaining production efficiency. To overcome this challenge, an effective approach involves utilizing numerical simulations to optimize temperature cycles during curing. Nonetheless, creating such a model is complex as it must consider multiple factors concurrently, including temperature release from chemical reactions, shrinkage strains, and stress resulting from temperature variations, topics covered in this package. The package begins with an introduction to fiber-reinforced composites, exploring their advantages, applications, and categorization. It guides you through the fabrication process, detailing curing techniques and associated challenges. Furthermore, the package introduces constitutive equations for simulating the curing process and the necessary Abaqus subroutines for implementation. Additionally, two practical workshops are included to offer experience in modeling the curing process with Abaqus. These workshops enable you to evaluate internal heat generation and analyze strain and stress distributions. They not only provide guidance on simulation and subroutine implementation but also are provided for verification purposes.
Creep Analysis in Abaqus
In engineering, creep phenomenon refers to the gradual deformation or strain that occurs in a material over time when it is subjected to a constant load or stress (usually lower than yield stress) at high temperatures. It is a time-dependent process that can lead to the permanent deformation and failure of the material if not properly accounted for in design considerations. Creep analysis is vital in engineering to understand material behavior under sustained loads and high temperatures. It enables predicting deformation and potential damage, ensuring safe and reliable structures. Industries like power generation and aerospace benefit from considering creep for long-term safety and durability of components.
In this training package, you will learn about Creep phenomenon and its related matters; you will learn several methods to estimate the creep life of a system’s components, such as Larson-Miller; moreover, all Abaqus models for the creep simulation such as Time-Hardening law and Strain-Hardening law will be explained along with Creep subroutine; also, there would be practical examples to teach you how to do these simulations.
Abaqus Damage Model for Thermoplastic Polymers with UMAT Subroutine
Thermoplastic polymers are materials composed of long molecular chains primarily consisting of carbon. These polymers possess the unique ability to be shaped and molded under heat and pressure while retaining their stability once formed. This high formability makes them widely used in various industries, including furniture production, plumbing fixtures, automotive components, food packaging containers, and other consumer products. This package introduces a thermodynamically consistent damage model capable of accurately predicting failure in thermoplastic polymers. The implementation of this model is explained through the use of an ABAQUS user material (UMAT) subroutine.
The package is structured as follows. The introduction section Provides an overview of thermoplastic polymers and their mechanical properties. In the Theory section, the constitutive damage model and its formulation are reviewed. Then, an algorithm for numerically integrating the damage constitutive equations is presented in the Implementation section. In the UMAT Subroutine section, a detailed explanation of the flowchart and structure of the subroutine is provided. Finally, two simulation examples, namely the T-fitting burst pressure test and the D-Split test, are performed and the obtained results, are investigated.
Notice: Software files and A full PDF guideline (Problem description, theory, ...) are available; Videos are coming soon.
DISP and VDISP Subroutines in ABAQUS
In a very simple form, DISP and VDISP subroutines are used to define user-defined boundary conditions. For example, when you need to define a boundary condition to be time-dependent, location-dependent, or even both, you should use the DISP and VDISP subroutines. ABAQUS features cannot be sufficient for problems with location-dependent and time-dependent boundary conditions simultaneously. In these cases, this subroutine can be useful to solve the challenges. In This package, you will understand the usages of these subroutines and how to work with them in three conceptual and simple workshops.
Simulation of Hyperelastic Behavior of Materials
Learn to simulate the mechanical behavior of soft materials like polymers and hydrogels using Abaqus. Understand hyperelasticity and the strain-energy equations that describe it. Discover different models for this behavior, choose the best one, optimize its parameters, and ensure it works well for your material. Validate your simulation with real-world data. Finally, master Abaqus tools to set up and run simulations for hyperelastic materials and structures.
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Modeling Functionally Graded Materials (FGMs) in ABAQUS
Dive into the realm of innovative engineering with our comprehensive tutorial package, designed to empower you in modeling Functionally Graded Materials (FGM) using the Abaqus USDFLD subroutine. Uncover the fascinating world of FGMs, materials that ingeniously vary their composition and microstructure, offering a nuanced control over mechanical, thermal, and other properties.
The workshop component takes you on an exploration of crack paths in Spherical Functionally Graded Materials, emphasizing simulation techniques using Abaqus Standard and the USDFLD subroutine. Uncover the secrets of stress distribution within a pressured, empty sphere, and enhance your skills by implementing the XFEM method for precise crack characterization. This training ensures you gain valuable insights into subroutine development, empowering materials engineers and designers to innovate and elevate the performance of structures across various industries. Embark on your journey to mastery with this all-encompassing tutorial package.
Composite Pressure Vessel simulation in ABAQUS
Pressure vessels are made using different methods today, and one of them is filament winding. This package shows the simulation of composite pressure vessels made using the filament winding method.
In this training package, three winding methods, planar, geodesic, and isotensoid, have been taught for filament winding pressure vessels. In this tutorial, two general methods also have been presented for simulating filament wound pressure vessels. One uses the Abaqus graphical user interface(GUI), and the other uses the Python script. On the other hand, two criteria, Tsai-Hill and Puck, have been used to model damage in the composite. A UMAT subroutine has been used to use the Puck criterion.
Composite pressure vessel analysis with Semi-Geodesic winding
Nowadays, pressure vessels are produced using various methods, one of which is filament winding. This package teaches the simulation of composite pressure vessels produced using the filament winding method. Filament winding itself has different methods, and one of the most widely used winding methods for producing composite vessels is the semi-geodesic filament winding method. In this package, first, the semi-geodesic method is described. Then, the simulation of a semi-geodesic vessel is performed using a Python script. Additionally, a UMAT subroutine is used to simulate the failure of composite materials used in the vessel.
Ductile Damage Abaqus model for 3D continuum element (VUMAT Subroutine)
In this package, the continuum damage mechanics framework for ductile materials is implemented and developed in ABAQUS by VUMAT Subroutine.
Constitutive modeling is treated within the framework of continuum damage mechanics (CDM) and the effect of micro-crack closure, which may decrease the rate of damage growth under compression, is incorporated and implemented.
The present package has been organized as follows. In the Introduction section, the basis of the CDM in ductile materials is explained, and the applications of the CDM are stated. In the Theory section, the CDM model formulation is briefly reviewed, and with micro-crack closure, the effect is described. In the Implementation section, an algorithm for the numerical integration of the damage constitutive equations is presented. In the VUMAT Subroutine section, the flowchart of the subroutine, and the subroutine structure, step by step, are explained in detail. How to run the VUMAT Subroutine in ABAQUS will be presented in this section. In the Verification section, the validation and verification of the numerical implementation will be evaluated, and the stability, convergence and accuracy of the results will be investigated. In the Application section, the applications of using the ductile damage model in mechanical processes are presented, and the prediction of damage growth and failure in mechanical processes is investigated.
Composite Fatigue Simulation with VUMAT Subroutine in ABAQUS
This training package consists of four chapters that help engineers and researchers in the industry to understand the fundamental concepts and necessary tools for simulating composite fatigue using VUMAT subroutine in ABAQUS. The first chapter provides an overview of the fatigue behavior of composite materials, including the factors contributing to fatigue failure. The second chapter explores the failure mechanisms of composite materials and the types of damage that can occur. The third chapter discusses the effects of fatigue on composite materials, including how it affects the material's properties and performance. Finally, the fourth chapter focuses on using the VUMAT subroutine in ABAQUS for composite fatigue analysis, including the material models and criteria used to simulate the behavior of composite materials under various loading conditions. By mastering the concepts and tools presented in this package, engineers can develop more durable and reliable composite structures that can withstand cyclic loading over extended periods of time.
Hardening plasticity in Abaqus
In this package, hardening plasticity in the Abaqus software using Abaqus material models or UMAT subroutine or UHARD subroutine is discussed. It should be mentioned using a subroutine to define hardening could be more professional and this package tries to familiarize users with these subroutines for hardening definitions. So, if you want to write these subroutines for your customized project in the hardening plasticity field, I recommend you the "UMAT Subroutine (VUMAT Subroutine) introduction" and "UHARD Subroutine (VUHARD Subroutine) in ABAQUS".
Simulation of composite Puck damage in 3d continuum element in Abaqus (UMAT-USDFLD-VUMAT)
The Puck criterion is an essential damage model for composite materials, considering both fiber and matrix failures simultaneously. It provides a practical way to predict the onset of damage in composites under various loading conditions. This training package is focused on simulating composite PUCK damage in 3D continuum elements using UMAT, VUMAT, and USDFLD subroutines in Abaqus. It covers different types of failure in composites, including fiber failure, matrix cracking, delamination, and interfacial failure, as well as criteria for predicting failure modes in composites that are dependent or not dependent on each other, such as the Tsai-Wu and Tsai-Hill criterion, respectively. Additionally, the package covers composites' most commonly used damage criteria, including the Puck criterion. The package provides step-by-step guidance on simulating composite Puck damage using each of the subroutines mentioned above in Abaqus.
Wood damage simulation with Abaqus subroutine | Wood damage FEM
We concentrate on wood composite deterioration using Sandhas and Hashin failure criteria in this training manual. First, we introduce the failure criteria and associated equations in this package. The damage models' flowchart is then described. The next phase involves trying to explain two subroutines line by line. Finally, we demonstrate the use of these two subroutines in two separate workshops and talk about the outcomes.
Simulation of woven composite damage in Abaqus
Woven composites are net-shaped composite structures that are fully interconnected by their yarns. Like a piece of cloth, the yarns are weaved together as warp and weft to create a composite structure. This package includes several components. First, it begins with an introduction to woven composites. Next, it provides a detailed explanation of macro modeling and offers guidance on how to perform it. The damage criteria employed in this package is a modified version of the Hashin criteria specifically designed for woven composites. Furthermore, the package demonstrates how to model damage using the USDFLD subroutine and Hashin relations. The subroutine is thoroughly explained, line by line, and a workshop is conducted to facilitate learning and practical application. Finally, the subroutine's validity is confirmed through a verification process.
Fatigue damage simulation of short fibre composites with subroutine
Fatigue failure in materials occurs when repetitive or fluctuating stresses, below the ultimate strength and often below the yield limit, lead to sudden and unpredictable failure, making it a significant concern in engineering due to its potential for catastrophic consequences. The reinforced part of the fiber-reinforced composites can be categorized as continuous or discontinuous, with the latter referred to as short fiber-reinforced composites. In this training package, the fatigue of short (chopped) fiber composites is explained. Two fatigue damage models are presented for short fiber composites: Nouri fatigue damage model and Avanzini fatigue damage model. The Nouri’s model is applicable for composites with orthotropic behavior. But the Avanzini’s model has considered the fiber distribution in the matrix to be homogeneous and random. It has assumed the material behavior to be isotropic. Also, Nouri's model was developed for strain-controlled test, but Avanzini's model was developed for stress-controlled test. In this tutorial, we use the Avanzini’s model, which is base on this article: “Fatigue behavior and cyclic damage of peek short fiber reinforced composites”. This article has implemented the USDFLD subroutine, but we use the UMAT subroutine, which is more accurate than USDFLD since the material strength and properties reduction is smooth. A standard test specimen is used in this simulation to model such behavior. You will learn the details in the package.
Simulation of woven composite fatigue in Abaqus
The training package focuses on simulating woven composite fatigue using Abaqus software and the modified Hashin fatigue damage model based on the article titled "Life prediction of woven CFRP structure subject to static and fatigue loading ". Woven composites have high strength and stiffness-to-weight ratios, but the interlacing pattern can affect stress distribution and damage mechanisms, making fatigue analysis crucial. The package includes four lessons covering different types of composite fatigue models, material characterization, generalization of the failure model, and the implementation of the UMAT subroutine. Two workshops provide hands-on experience in implementing the UMAT subroutine on one element in cyclic tension and a complex model. Fatigue analysis predicts material behavior under cyclic loading and helps design safe and reliable structures.
UMAT Subroutine (VUMAT Subroutine) in ABAQUS-Free Version- UMAT Abaqus example
This package includes the free version of the two following packages. The following packages include 11 workshops for writing different types of subroutines and give you instructions and points to write your own UMAT/VUMAT subroutine. Here, a UMAT Abaqus example is free to download.
"UMAT Subroutine (VUMAT Subroutine) introduction" is used when the material model is not available in ABAQUS software. If you follow this tutorial package, including standard and explicit solver, you will have the ability to write, debug and verify your subroutine based on customized material to use this in complex structures. These lectures are the introduction to writing advanced UMAT and VUMAT subroutines in hyperelastic Martials, Composites, and Metal, and so on. Watch Demo
"Advanced UMAT Subroutine (VUMAT Subroutine)" training package helps Abaqus users to prepare complex UMAT and VUMAT subroutines. This training package is suitable for those who are familiar with subroutine or want to learn UMAT/VUMAT subroutine Professionally. Equations for computational plasticity based on kinematic stiffness are also discussed. In addition, metal damage has been implemented based on Johnson Cook's model. Watch Demo
Simulation of SMA in Abaqus with UMAT
Shape-memory alloys (SMAs) have the ability to recover their original shape, thanks to the shape-memory effect and superelasticity. These unique characteristics have led to the broad usage of SMAs in engineering and medical applications. Simulations offer cost-effective methods for analyzing SMAs’ behavior, ultimately enhancing their reliability and performance. Consequently, researchers frequently employ simulations to investigate SMA-based systems. This educational package begins by exploring the fundamentals of SMA wires, presenting their various types and specific capabilities. It then provides the necessary constitutive equations to describe the behavior of SMAs in simulation. The package includes a flowchart and a step-by-step guide for writing a subroutine to model SMAs in Abaqus. Users will also discover a workshop that uses Abaqus to simulate the superelasticity effect in SMA wires. This workshop not only offers guidance on the simulation and the implementation of the subroutine, but also compares the result with an analytical solution for verification.
Simulation of composite Hashin damage in 3d continuum element in Abaqus (UMAT-VUMAT-USDFLD)
In this training package, the 3D continuum HASHIN damage initiation model is prepared via three subroutines (USDFLD, UMAT and VUMAT).This training package teach you subroutines line-by-line. It should be noted that after damage initiation, failure occurs suddenly and in the form of a reduction in properties in the model. The HASHIN theory for this package is based on Kermanidis article titled” FINITE ELEMENT MODELING OF DAMAGE ACCUMULATION IN BOLTED COMPOSITE JOINTS UNDER INCREMENTAL TENSILE LOADING “.
Lemaitre Damage model implementation with VUMAT Abaqus
The Lemaitre damage model is now widely used to deal with coupled damage analyses for
various mechanical applications.
In this package, Firstly, we try to introduce the Lemaitre damage model, including damage mechanics and formulation of the Lemaitre damage model. Then, writing the Lemaitre subroutine is reached step by step. To do this job, the flowchart of the subroutine, Writing the subroutine line by line, implementation of the subroutine in one element and verification is done. In the last chapter, we implement this subroutine in a complex problem, the upsetting process.
