"Computational Manufacturing and Materials Research Lab of Professor Tarek I. Zohdi"

NNMI Manufacturing Demonstration Center

Laser Sintering

Additive manufacturing refers to a relatively recent group of manufacturing technologies whereby one can “3D print” parts, which has the potential to significantly reduce waste and alter the entire industry. Selective laser sintering/ melting (SLS/ SLM) is one type of additive manufacturing technology with the distinct advantage of being able to 3D print metals. Read more…

Flowing Particulate Media

Flowing particulate media are ubiquitous in a wide spectrum of applications that include transport systems, fluidized beds, manufacturing and materials processing technologies, energy conversion and propulsion technologies, sprays, jets, slurry flows, and biological flows. Read more…

Bullet Impact on Ballistic Fabric

High strength textiles are a fundamental component of armors in multiple applications, where they are coupled with metal and ceramic plates and various other systems. In this research, the effect of applying electromagnetic fields to a ballistic fabric undergoing impact is explored, wherein an external magnetic field induces deformation in an electrified sheet to influence the behavior of the projectile. Read more…

Research Thumbnails

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Fully Three-Dimensional Process Planning for Additive Manufacturing

  Research by: Maxwell Micali While additive manufacturing and 3D printing have achieved notoriety for their abilities to manufacture complex three-dimensional parts, the state of the art is not truly three-dimensional. Rather, the process plans rely on a stack of discretized two-dimensional layers. Discretization of smooth, freeform features results in printed parts with stair-stepped surfaces, increasing the total volumetric error of the part and potentially diminishing the intended performance of functional surfaces. By performing process planning in a fully three-dimensional domain, as opposed to the 2.5D status quo, the...

Particle method to simulate the flow through marine current turbines

  Research by: David Fernandez-Gutierrez The Ocean represents a massive energy resource that can be employed for electricity generation. This fact has led to the growing interest ocean-driven energy generation over the last decade. This research project focuses on the development of a novel particle method to simulate the flow through marine current turbines. Ultimately, the goal of the project is to evaluate the probability and potential damage of collisions on the turbine blades from solid elements dragged by currents, and to optimize design modifications to mitigate such events. The proposed numerical method arises from...

Non-invasive repair of piping systems

  Research by: Zeyad Zakey The use of piping systems is ubiquitous in several engineering applications, including process plants, factories, and oil refineries. Concerning the latter, it is of priority to maintain structural integrity of all systems to ensure constant operation. However, due to natural wear and tear, corrosion, or other else, piping systems may become damaged during use. In order to repair the system, it must be isolated. This entails stoppage of operation, resulting in loss of operating time and profit. The aim of this project was to...

Multi-scale particle methods for improved heat transfer

Syd Hashemi email: sydhashemi@berkeley.edu Research description Overview Although computer simulation power has astronomically increased since the beginning of the simulation by computers, and still is increasing, machine performance is still a limiting factor. This primarily restricts the size of the system that can be simulated, for example in the case of molecular dynamics the number of particles that can be handled with the computer, and the number of timesteps that can be calculated during the simulation is part of this restriction. Besides, to capture an important phenomena in the...

Numerical Simulation of Laser Ablation of Diamond for Micro-machine Tooling

  Research by: Marc Russell Micro-machining operations utilize micro-scale machine tools to carry out traditional manufacturing process (e.g. milling, drilling, etc. ) on microscale parts. They can be used for part creation as well as surfacing . Binder-less polycrystalline diamond (BPLCD) has been cited as an ideal machine tool material due to its superior mechanical properties (higher hardness, higher wear resistance, isotropic material properties, etc.) to that of the conventional diamond materials usually used for such tooling. However, because of these properties it is difficult to produce BPLCD tooling...

Numerical Simulation of Selective Laser Melting Process

  Research by: Marc Russell Additive Manufacturing(AM), a.k.a. 3D printing, is a rapidly emerging technology that will revolutionize the manufacturing world by allowing for the production of net-shape, customizable, ready-to-use parts in a matter of hours. AM parts are built-up layer-by-layer from raw materials, under computer control in the image of a digital model. Selective Laser Melting of particle beds (SLM) is a particularly promising AM technique for producing complex 3D metallic structures through a repetitive process of deposition and guided laser melting of a bed of microscale, metallic...

Particle Based Simulation Framework for Sintered Mechanical Components

  Research by: Chang Yoon Park A Discrete Element Approach was used to create a framework for mechanical simulations of sintered materials. Bond stiffness between the particles were determined by performing eigenvalue analysis.
If the stored energy in the bonds exceeds the pre-determined fracture surface energy, the bonds were deactivated to simulate fracture. A 3 Point Bending test was performed as an...

Computational Multi-Phase Materials Design

Research by: Santiago Miret Ceramic Matrix Composite (CMC) materials are becoming more and more important for high temperature and high stress environments, such as those found in aerospace and automotive applications. The aim of this project is to create a design tool for CMCs using numerical methods to compute the effective properties of the materials and to simulate their behavior in high stress...

Holographic Diffractive Optics for Stereolithography

  Research by: Brett Kelly Existing additive manufacturing techniques tend to operate by printing of two-dimensional cross-sections layered on top of one another to form a three dimensional geometry. Optical printing techniques such as photopolymerization by stereolithography have the potential to move towards “true” 3D printing through the use of holographic light shaping. By controlling the phase of an incident coherent wave front there is potential to pattern light in 3 dimensions and cure non-planar geometries in a single exposure. This offers the advantages of increased print speed, the...

Modeling and simulation of the multi-jet printing process

  Research by: Shanna Tune Additive Manufacturing (AM), more commonly known as 3D printing, is the process of building up material layers to produce a final product capable of having freeform geometries and internal structures. Most AM processes utilize polymer and plastic materials which have limited applications due to the anisotropic material response resulting from the layer-by-layer construction and generally poor fine feature resolution. One polymer based process, the material jetting process, or Multi-Jet Printing (MJP), has a potential for increased use as the technique is capable of producing...

Computational research on self-assembly in a micro/nano scale

  Research by: Dong Hoon Kim Although the demand for miniaturized products is increasing these days, existing manufacturing robots in serial production systems seem to have difficulties in producing miniature products because they have had to become increasingly larger to properly complete precise machining. Therefore, small-scale self-assembly could provide economic and efficient solutions to overcome this limitation. Also, the self-assembly of 3D structures at the micro scale could make it possible to fabricate new materials. The characteristics of different materials could be combined to produce advanced engineering materials including...

Modeling and simulation of functionalized materials for 3-D printing

  Research by: Erden Yildizdag 3-D printing also known as additive manufacturing has an increasing demand in the industry to manufacture different kinds of devices. Thus, materials used for 3-D printing need to have different properties (electrical, magnetic, thermal, mechanical, etc.) depending on what we are manufacturing. The aim of this project is modeling new functionalized materials and look for their performances with numerical and experimental studies. Firstly, overall response of the new functionalized material is investigated using multi-scale computational homogenization techniques as numerical tool. After that, different materials...

Construction procedure for TC panels

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Beam Based Modeling of Open-Celled Foams

Research by: Matthew Kurry With modern polymer and composite technology helmets used by military personnel have become so good at preventing death from kinetic impacts that soldiers are surviving attacks that would have killed them before. While more soldiers are surviving, the momentum transfer due to the impact can injure the wearer’s brain. In this research we seek to understand the momentum and energy transfer physics of open-celled foams to better protect helmet wearers. Various projects in this research include the processing of scanned foam images and the used...

Modeling and simulation of particle doped materials under an electromagnetic field

Bhavesh Patel email: b.patel@berkeley.edu Research description Overview The interests of this research are particle doped composites materials, made by adding particles into a base material commonly called matrix material. The focus is on potential application for micro electromagnetic devices such as magnetic cores for planar inductor or nano composite capacitors. Based on these applications, the objective is to propose a numerical tool that allows simulating behavior of micro/nano particle doped material under an electromagnetic (EM) field. Specifically, knowing the external EM field the composite is immersed in, we want:...

Soil Simulations in Subterranean Blasts

Research by: Matthew Kury Underground blasts are of particular interests to civilian miners as well as military defense contractors. Soils are complicated composite of grains, fluids and other materials, which are often blown out during explosions. The complicated nature of the event requires a multi-method approach in order to capture the physics of the event and to make simulating the event possible. I am developing a parallel discrete element code to capture the behavior of the soil near the blast event and a finite element code to represent the...

Energy Efficient Facades for Buildings

Research by: Aashish Ahuja Lighting consumes a substantial amount of energy in buildings that has made it imperative to depend more on daylighting.                                                    My research tries to computationally assess the qualities of a novel light-channeling facade subsystem called ‘Translucent Concrete’ (TC).   I conduct various simulations on my model, starting with: 1) Ray Tracing to estimate the performance of the TC system during the day.  ...

Operational Analysis of Artificial Photosynthetic Systems

  Research by: John Stevens I build computational models to predict the net fuel energy harvest by and light transmission through multiphase wireless photoelectrochemical systems that use optical concentration. With these models, I assess optimal designs to accommodate different solar tracking methodologies, photovoltaic cells, catalysts, deployment locations, optical concentration ratios and cell geometries. This allows me to propose designs to reduce energy costs, primary energy inputs and efficiency losses, while enhancing device lifetime. Additionally, I use computational models and experimental processes to study the effects of heat transfer on...

Thermal Barrier Coatings

Research by: Peter Minor To protect against high temperatures, gas turbines use highly porous ceramic thermal barrier coatings (TBCs) which are susceptible to erosion and foreign object impact damage. Few numerical tools exist which are capable of both accurately capturing the specific failure mechanisms inherent to TBCs and iterating design parameters without the requirement for coupled experimental data. To overcome these limitations, I’m developing a discrete element model (DEM) to simulate the microstructure of a TBC using a large-scale assembly of bonded particles. The particles can be combined to...

Electromagnetically Sensitive Ballistic Fabric

Research by: Alejandro Queiruga High strength textiles are a fundamental component of armors in multiple applications, where they are coupled with metal and ceramic plates and various other systems. In this research, the effect of applying electromagnetic fields to a ballistic fabric undergoing impact is explored, wherein an external magnetic field induces deformation in an electrified sheet to influence the behavior of the projectile. The interaction between the applied electromagnetic fields and the resulting range of forces that can be applied onto the moving projectile is modeled by simplified...

Multiphysical Modeling and Simulation of Selective Laser Sintering

Research by: Rishi Ganeriwala Additive manufacturing refers to a relatively recent group of manufacturing technologies whereby one can “3D print” parts, which has the potential to significantly reduce waste and alter the entire industry. Selective laser sintering/ melting (SLS/ SLM) is one type of additive manufacturing technology with the distinct advantage of being able to 3D print metals. In SLS/ SLM parts are built up layer-by-layer out of powder particles, which are selectively melted via a laser. However, in order to produce defect free parts of sufficient strength, the...

Flowing particulate media

Flowing particulate media are ubiquitous in a wide spectrum of applications that include transport systems, fluidized beds, manufacturing and materials processing technologies, energy conversion and propulsion technologies, sprays, jets, slurry flows, and biological...

Colliding and Flowing Particles

Flowing particulate media are ubiquitous in a wide spectrum of applications that include transport systems, fluidized beds, manufacturing and materials processing technologies, energy conversion and propulsion technologies, sprays, jets, slurry flows, and biological flows. The discrete nature of the media, along with their underlying coupled multi-physical interactions can lead to a variety of interesting phenomena, many of which are unique to such media. My research explores the utility of numerical simulations based on the discrete element method and collision driven particle dynamics methods for analyzing flowing particulate media. I...

Ablation

  Roll-to-roll manufacturing has the potential to be a high throughput and low cost technique for producing flexible electronics. Currently, however the inability to control the flow of the inks precisely prevents the creation of the sharp and small features needed to produce electronics. In my research, I am using the Discrete Element Method (DEM) to explore the whether laser ablation can be used to improve the properties of the printed features. A general DEM simulation environment has been written allowing for multiple element types each with distinct properties...