Digital manufacturing

Digital Manufacturing

Digital Manufacturing is an integrated approach to manufacturing that is centered around a computer system. The transition to the digital manufacturing has become more popular with the rise in quantity and quality of computer hardware at manufacturing plants. As more automated tools have become used in manufacturing plants it has become necessary to model, simulate, and analyze all of the machines, tooling, and input materials in order to optimize the manufacturing process. Overall digital manufacturing can be seen as sharing the same goals as computer-integrated manufacturing (CIM), flexible manufacturing, lean manufacturing, and design for manufacturability (DFM). The main difference is that digital manufacturing was evolved for use in the computerized world.

Three Dimensional Modeling

Manufacturing engineers use 3D modeling software to design the tools and machinery necessary for their intended applications. The software allows them to design the factory floor layout and the production flow. This technique lets engineers analyze the manufacturing process and to search for ways to increase efficiency in production before any production even begins.

Simulation

Simulation can be used to model and test a system's behavior, as well providing engineers with a tool for inexpensive, fast, and secure analysis to test how changes in a system can affect the performance of that system.

These models can be classified into :

• Static - comprised of a system of equations at a point in time
• Dynamic - System of equations that incorporate time as a variable

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  Robcad is a popular software used in digital manufacturing. Models of automated machinery and production lines can be created and simulated in real time.

  Continuous - Dynamic model where time passes linearly
• Discrete - Dynamic model where time is separated into chunks
• Deterministic - Models where a unique solution is generated per a given input
• Stochastic - Models where a solution is generated utilizing probabilistic parameters

Applications of simulation can be assigned to:

• Product design such as virtual reality
• Process design; assisting in the design of manufacturing processes
• Enterprise resource planning

Analysis

Digital manufacturing systems often incorporate optimization capabilities to reduce time and cost, and improve the efficiency of most processes. These systems improve optimization of floor schedules, production planning, and decision making. The system analyzes feedback from production, such as deviations or problems in the manufacturing system, and generates solutions for handling them.

In addition, many technologies analyze data from simulations in order to calculate a design that is optimal before it is even built.

A CNC waterjet cutter is an example of the types of computer controlled tooling that are essential to digital manufacturing.

Tooling

There are many different tooling processes that digital manufacturing utilizes. However, every digital manufacturing process involves the use of computerized numerical control (CNC). This technology is crucial in digital manufacturing as it not only enables mass production and flexibility, but also provides a link between a CAD model and production. As a result, major strides in additive manufacturing have been realized and are at the forefront of digital manufacturing. These processes allow machines to address every element of a part no matter the complexity of its shape. These processes can be classified into the following:

• Stereolithography - In this process, solid parts are formed by solidifying layers of a photopolymer with ultraviolet light. There is a wide range of acrylics and epoxies that are used in this process.
• Ink-Jet Processing - Although the most widely used ink-jet process is used for printing on paper, there are many that are applied in engineering. This process involves a printhead depositing layers of liquid material onto a filler powder in the shape of the desired object. After the powder is saturated, a fresh new layer of powder is added continually until the object is built.
• Laser sintering and fusion - This process utilizes heat produced by infrared lasers to bond a powdered material together to form a solid shape.
• Sheet lamination - This process divides a 3D object into sections where it builds the object layer by layer using a flowable material.
• Extrusion modeling - In this process, thermoplastic resin in heated and then extruded through a nozzle. The extruder travels around the outside of the object being built and builds the inside by hatching.

Benefits of Digital Manufacturing

• Optimization of a parts manufacturing process. This can be done by modifying and/or creating procedures within a virtual and controlled environment. By doing this the use of new robotic or automated systems can be tested in the procedure before being physically implemented. [1]
• Digital manufacturing allows for a the whole manufacturing process to be created virtually before it is implemented physically. This enables designers to see the results of their process before investing time and money into creating the physical plant. [1]
• The affects caused by changing the machines or tooling processes can be seen in real-time. This allows for analysis information to be taken for an individual part at any desired point during the manufacturing process. [1]

Types of Digital Manufacturing

On Demand

• Additive - Additive manufacturing is the "process of joining materials to make objects from 3D model data, usually layer upon layer." Digital Additive manufacturing is highly automated which allows unattended building, machine utilization, and reduced cost. By incorporating model data from digitized open sources, products can be produced quickly, efficiently, and cheaply.
• Rapid - Much like Additive manufacturing, Rapid manufacturing use digital models to rapidly produce a product that can be complicated in shape and heterogeneous in material composition. Rapid manufacturing utilizes not only the digital information process, but also the digital physical process. Digital information governs the physical process of adding material layer by layer until the product is complete. Both the information and physical processes are necessary for rapid manufacturing to be flexible in design, cheap, and efficient.  

Cloud-based design and manufacturing

Cloud-Based Design (CBD) refers to a model that incorporates social network sites, cloud computing, and other web technologies to aid in cloud design services. This type of system must be cloud computing-based, be accessible from mobile devices, and must be able to manage complex information. AutoDesk 123D is an example CBD.

Cloud-Based Manufacturing (CBM) refers to a model that utilizes the access to open information from various resources to develop reconfigurable production lines to improve efficiency, reduce costs, and improve response to customer needs.