Towards Assembly-Free Methods for Additive Manufacturing Simulation

2015 ◽  
Author(s):  
Anirudh Krishnakumar ◽  
Krishnan Suresh ◽  
Aaditya Chandrasekar
Keyword(s):  
Additive Manufacturing ◽  
Stiffness Matrix ◽  
Deposition Process ◽  
Implementation Challenges ◽  
Advantages And Disadvantages ◽  
Material Deposition ◽  
Element Simulation ◽  
Non Linear ◽  
Global Stiffness Matrix ◽  
Linear Systems Of Equations

There is significant interest today in the finite element simulation of various Additive Manufacturing (AM) processes. AM simulation is time-dependent, inherently non-linear, and involves multiple physics. In addition, repeated meshing and insertion of new elements during material deposition can pose significant implementation challenges. Currently, AM simulation is handled either through a ‘quiet’ approach or an ‘inactive’ approach. In the quiet approach, all finite elements within the workspace are assembled into the global stiffness matrix, and the elements yet to be deposited are assigned ‘void’ material properties. In the inactive approach, only the elements that have been deposited are assembled into the global stiffness matrix. The advantages and disadvantages of the two methods are well documented. In this paper, we propose a voxel-based, assembly-free framework for AM simulation. This framework presents several advantages including. (1) The workspace is meshed only once at the start of the simulation, (2) addition and deletion of elements is trivial, (3) reduced memory requirement as the global stiffness matrix is never assembled and (4) the underlying linear systems of equations can be solved efficiently through assembly-free methods. We demonstrate the framework here by simulating transient non-linear thermal behaviour of a laser deposition process, with material deposition.

scholarly journals Investigating the Mechanics of Hybrid Metal Extrusion and Bonding Additive Manufacturing by FEA

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 811 ◽  
Author(s):  
Jørgen Blindheim ◽  
Torgeir Welo ◽  
Martin Steinert
Keyword(s):  
Additive Manufacturing ◽  
Material Flow ◽  
Deposition Process ◽  
Feed Speed ◽  
Element Analysis ◽  
Reduced Pressure ◽  
Metal Structures ◽  
Material Deposition ◽  
Flow Through ◽  
Metal Extrusion

Hybrid Metal Extrusion & Bonding Additive Manufacturing (HYB-AM) is a hybrid manufacturing technology for the deposition of layered metal structures. This new deposition process is a complex metal forming operation, yet there is significant lack of knowledge regarding the governing mechanisms. In this work, we have used finite element analysis (FEA) to study material flow in the extruder, as well as the conditions at the interfaces of the deposited extrudate and the substrate, aiming to identify and characterize the process parameters involved. Analysis of the material flow shows that the extrusion pressure is virtually independent of the deposition rate. Furthermore, from the simulations of the material deposition sequence, it is clearly visible how the contact pressure at the interface will drop below the bonding threshold if the feed speed is too high relative to the material flow through the die. The reduced pressure also leads to the formation of a ‘gas-pocket’ inside the die, thus further degrading the conditions for bonding. The analyses of the process have provided valuable insights for the further development and industrialization of the process.

Finite Element Simulation of Localized Electrochemical Deposition for Maskless Electrochemical Additive Manufacturing

2015 ◽  
Vol 137 (1) ◽  
Author(s):  
Anne M. Brant ◽  
Murali M. Sundaram ◽  
Abishek B. Kamaraj
Keyword(s):  
Additive Manufacturing ◽  
Process Parameters ◽  
Three Dimensional ◽  
Deposition Process ◽  
Specific Process ◽  
Manufacturing Technique ◽  
Element Simulation ◽  
Interelectrode Gap ◽  
Linear And Nonlinear ◽  
High Control

Localized electrodeposition (LED) was explored as an additive manufacturing technique with high control over process parameters and output geometry. The effect of variation of process parameters and changing boundary conditions during the deposition process on the output geometry was observed through simulation and experimentation. Trends were found between specific process parameters and output geometries in the simulations; trends varied between linear and nonlinear, and certain process parameters such as voltage and interelectrode gap were found to have a greater influence on the output than others. The simulations were able to predict the output width of deposition of experiments in an error of 8–30%. The information gained from this research allows for greater understanding of LED output, so that it can potentially be applied as an additive manufacturing technique of complex three-dimensional (3D) parts on the microscale.

Development of a high-speed laser material deposition process for additive manufacturing

2021 ◽  
Vol 33 (1) ◽  
pp. 012021
Author(s):  
Jonathan Schaible ◽  
Lennart Sayk ◽  
Thomas Schopphoven ◽  
Johannes Henrich Schleifenbaum ◽  
Constantin Häfner
Keyword(s):  
Additive Manufacturing ◽  
High Speed ◽  
Deposition Process ◽  
Laser Material ◽  
Material Deposition

A Network Based Modelling Approach Using the Dimensional Analysis Conceptual Modeling (DACM) Framework for Additive Manufacturing Technologies

2016 ◽  
Author(s):  
Hossein Mokhtarian ◽  
Eric Coatanéa ◽  
Henri Paris ◽  
Tuomas Ritola ◽  
Asko Ellman ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Dimensional Analysis ◽  
System Architecture ◽  
Conceptual Modeling ◽  
Deposition Process ◽  
Illustrative Case ◽  
Influence Of Process Parameters ◽  
Modelling Framework ◽  
Material Deposition ◽  
Manufacturing Technologies

The application of additive manufacturing technologies in the industry is growing fast. This leads to an increasing need for reliable modeling techniques in the field of additive manufacturing. A methodology is proposed to systematically assess the influence of process parameters on the final characteristics of additively manufactured parts. The current study aims at presenting a theoretical framework dedicated to the modeling of the additive manufacturing technology. More specifically, the framework is used in the context of the study to plan and optimize the experimental process to minimize the amount of experiments required to populate the model. The framework presented is based on the Dimensional Analysis Conceptual Modelling framework (DACM). DACM is an approach supporting the production of models. This approach is designing networks representing a system architecture and behavior using an approach sharing similarities with neural networks. Based on the proposed approach, it is possible to detect where supplementary experimental data have to be collected to complete the model generated by the DACM approach. The modeling of the Direct Material Deposition process is conducted as an illustrative case study. The scope of the approach is vast and supported by validated scientific methods combined to form the core of the DACM method. The DACM framework is step by step extracting information from a description of the system architecture to create semi-automatically a model that can be simulated and used for multiple types of analyses associated for example with innovation and design improvement. The current paper will focus on the usage of the DACM framework, recently developed in a project, in the field of additive manufacturing.

Additive Manufacturing of Multi-Material and Composite Parts

2020 ◽  
pp. 127-146
Author(s):  
V. Senthilkumar ◽  
Velmurugan C. ◽  
K. R. Balasubramanian ◽  
M. Kumaran
Keyword(s):  
Additive Manufacturing ◽  
Composite Materials ◽  
Functionally Graded Materials ◽  
Deposition Process ◽  
Functionally Graded ◽  
Subsequent Stage ◽  
Functional Requirements ◽  
Graded Materials ◽  
Material Deposition ◽  
Single Part

Additive manufacturing (AM) technology can be employed to produce multimaterial parts. In this approach, multiple types of materials are used for the fabrication of a single part. Custom-built functionally graded, heterogeneous, or porous structures and composite materials can be fabricated thorough this process. In this method, metals, plastics, and ceramics have been used with suitable AM methods to obtain multi-material products depending on functional requirements. The process of making composite materials by AM can either be performed during the material deposition process or by a hybrid process in which the combination of different materials can be performed before or after AM as a previous or subsequent stage of production of a component. Composite processes can be employed to produce functionally graded materials (FGM).

scholarly journals Low-Roughness-Surface Additive Manufacturing of Metal-Wire Feeding with Small Power

Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4265
Author(s):  
Bobo Li ◽  
Bowen Wang ◽  
Greg Zhu ◽  
Lijuan Zhang ◽  
Bingheng Lu
Keyword(s):  
Additive Manufacturing ◽  
High Surface ◽  
Deposition Process ◽  
High Energy ◽  
Width Ratio ◽  
Thin Wall ◽  
Small Power ◽  
High Surface Quality ◽  
Wall Structures ◽  
Wire Feed

Aiming at handling the contradiction between power constraint of on-orbit manufacturing and the high energy input requirement of metal additive manufacturing (AM), this paper presents an AM process based on small-power metal fine wire feed, which produces thin-wall structures of height-to-width ratio up to 40 with core-forming power only about 50 W. In this process, thermal resistance was introduced to optimize the gradient parameters which greatly reduces the step effect of the typical AM process, succeeded in the surface roughness (Ra) less than 5 μm, comparable with that obtained by selective laser melting (SLM). After a 10 min electrolyte-plasma process, the roughness of the fabricated specimen was further reduced to 0.4 μm, without defects such as pores and cracks observed. The ultimate tensile strength of the specimens measured about 500 MPa, the relative density was 99.37, and the Vickers hardness was homogeneous. The results show that the proposed laser-Joule wire feed-direct metal deposition process (LJWF-DMD) is a very attractive solution for metal AM of high surface quality parts, particularly suitable for rapid prototyping for on-orbit AM in space.

scholarly journals Development of an Additive Manufacturing System for the Deposition of Thermoplastics Impregnated with Carbon Fibers

2019 ◽  
Vol 3 (2) ◽  
pp. 35 ◽  
Author(s):  
Miguel Reis Silva ◽  
António M. Pereira ◽  
Nuno Alves ◽  
Gonçalo Mateus ◽  
Artur Mateus ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Additive Manufacturing ◽  
Carbon Fibers ◽  
Low Cost ◽  
Deposition Process ◽  
Processing Parameters ◽  
Yarn Diameter ◽  
Thermoplastic Matrix ◽  
Anisotropic Mechanical Properties ◽  
Long Carbon Fiber

This work presents an innovative system that allows the oriented deposition of continuous fibers or long fibers, pre-impregnated or not, in a thermoplastic matrix. This system is used in an integrated way with the filamentary fusion additive manufacturing technology and allows a localized and oriented reinforcement of polymer components for advanced engineering applications at a low cost. To demonstrate the capabilities of the developed system, composite components of thermoplastic matrix (polyamide) reinforced with pre-impregnated long carbon fiber (carbon + polyamide), 1 K and 3 K, were processed and their tensile and flexural strength evaluated. It was demonstrated that the tensile strength value depends on the density of carbon fibers present in the composite, and that with the passage of 2 to 4 layers of fibers, an increase in breaking strength was obtained of about 366% and 325% for the 3 K and 1 K yarns, respectively. The increase of the fiber yarn diameter leads to higher values of tensile strength of the composite. The obtained standard deviation reveals that the deposition process gives rise to components with anisotropic mechanical properties and the need to optimize the processing parameters, especially those that lead to an increase in adhesion between deposited layers.

scholarly journals An Improved Lagrangian-Inverse Method for Evaluating the Dynamic Constitutive Parameters of Concrete

Materials ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1871
Author(s):  
Xinlu Yu ◽  
Yingqian Fu ◽  
Xinlong Dong ◽  
Fenghua Zhou ◽  
Jianguo Ning
Keyword(s):  
High Speed ◽  
Inverse Method ◽  
Image Correlation ◽  
Analysis Method ◽  
Stress Strain ◽  
Optical Techniques ◽  
Element Simulation ◽  
Non Linear ◽  
Constitutive Parameters ◽  
Inverse Analysis Method

The dynamic constitutive behaviors of concrete-like materials are of vital importance for structure designing under impact loading conditions. This study proposes a new method to evaluate the constitutive behaviors of ordinary concrete at high strain rates. The proposed method combines the Lagrangian-inverse analysis method with optical techniques (ultra-high-speed camera and digital image correlation techniques). The proposed method is validated against finite-element simulation. Spalling tests were conducted on concretes where optical techniques were employed to obtain the high-frequency spatial and temporal displacement data. We then obtained stress–strain curves of concrete by applying the proposed method on the results of spalling tests. The results show non-linear constitutive behaviors in these stress–strain curves. These non-linear constitutive behaviors can be possibly explained by local heterogeneity of concrete. The proposed method provides an alternative mean to access the dynamic constitutive behaviors which can help future structure designing of concrete-like materials.

A New Method Tracing Load-Deflection Equilibrium Path of a Doubly Nonlinear Truss

2012 ◽  
Vol 166-169 ◽  
pp. 68-72
Author(s):  
Shu Tang Liu ◽  
Qi Liang Long
Keyword(s):  
Matrix Equation ◽  
Stiffness Matrix ◽  
Large Scale ◽  
New Method ◽  
Truss Structure ◽  
Equilibrium Path ◽  
Nodal Coordinates ◽  
Doubly Nonlinear ◽  
Global Stiffness Matrix

A new method tracing the load-deflection equilibrium path of a truss with doubly nonlinearity is proposed. The total global stiffness matrix equation has been formulated in terms of nodal coordinates, iteration formulations has been written through adopting a single control coordinate, so that an new method tracing the load-deflection equilibrium path has been proposed. Analysis results of Star dome truss and Schwedeler dome truss have shown that the proposed method is stable numerically, quick in convergence, high in degree of accuracy and easy in use. The proposed method can be used for large-scale truss structure.

OpenMp solvers for parallel finite element and meshless analyses

2014 ◽  
Vol 31 (1) ◽  
pp. 2-17 ◽  
Author(s):  
S.H. Ju
Keyword(s):  
Finite Element ◽  
Stiffness Matrix ◽  
Preconditioned Conjugate Gradient ◽  
Content Type ◽  
Minimum Requirement ◽  
Source Codes ◽  
Parallel Solution ◽  
Parallel Finite Element ◽  
Fortran 90 ◽  
Global Stiffness Matrix

Purpose – This paper develops C++ and Fortran-90 solvers to establish parallel solution procedures in a finite element or meshless analysis program using shared memory computers. The paper aims to discuss these issues. Design/methodology/approach – The stiffness matrix can be symmetrical or unsymmetrical, and the solution schemes include sky-line Cholesky and parallel preconditioned conjugate gradient-like methods. Findings – By using the features of C++ or Fortran-90, the stiffness matrix and its auxiliary arrays can be encapsulated into a class or module as private arrays. This class or module will handle how to allocate, renumber, assemble, parallelize and solve these complicated arrays automatically. Practical implications – The source codes can be obtained online at http//myweb.ncku.edu.tw/∼juju. The major advantage of the scheme is that it is simple and systematic, so an efficient parallel finite element or meshless program can be established easily. Originality/value – With the minimum requirement of computer memory, an object-oriented C++ class and a Fortran-90 module were established to allocate, renumber, assemble, parallel, and solve the global stiffness matrix, so that the programmer does not need to handle them directly.

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