### Geometric Modeling

The culture of design & manufacturing incorporates various crucial aspects for the production of a market efficient product. Computer-aided Engineering or CAE comes up as a central part of the entire manufacturing process. Over the years, the function of CAE has evolved so much that it has developed its applications depending upon the type of usage and execution.  Geometric Modeling happens to be one of the most popular CAE applications.

The computer/software generated mathematical representation of an object’s geometry is called Geometric Modeling. As curves are easy to manipulate and bend as per application, geometric modeling uses curves extensively to construct surfaces. The formation of curves can be achieved by,

A set of points,

Analytic functions, or

Other curves/functions

The mathematical representation of an object can be displayed on a computer and used for generation of drawings; which go on for analysis and eventual manufacturing of the object. In general, there are three conventional steps to create a geometric model:

• Creating key geometric elements by using commands like points, lines, and circles.
• Applying Transformations on the geometric elements using commands like rotation, achieve scaling, and other related transformations functions.
• Constructing the geometric model using various commands that integrates the elements of the geometric model to form the desired shape.
##### REPRESENTAION OF GEOMETRIC MODELS
• Two Dimensional or 2D: It projects a two-dimensional view and is used for flat objects.
• 1 2D: It projects the views beyond the 2D and enables viewing of 3D objects that have no sidewall details.
• Three Dimensional or 3D: This representation permits complete three-dimensional viewing of the model with intricate geometry. The most leading process of geometric modeling in 3D is Solid modeling.
##### TYPES OF GEOMETRIC MODELINGS

Depending upon the representations of objects, geometric modeling system can be classified into three categories, which are:

• Solid modeling

Also known as volume modeling, this is the most widely used method as it provides a complete description of solid modeling.

• Wireframe modeling

It is a simple modeling system, which is used to represent the object by the help of lines only. Hence, it is also known as Line model representation. However, wireframe modeling is not enough to express complex solids; therefore, it is used to describe only wiring systems.

• Surface modeling

This type of modeling represents the object by its surface, and it is used to describe the object with a clear view of manufacturing. By this clear point of view, surface modeling cannot be used to develop an internal surface of any model. Surface modeling uses Bezier and B-spines.

Requirements of Geometric Modeling

The various requirements of geometric modeling are as follows:

• The cross-section, hidden lines, dimensions are needed for Graphical Visualization.
• Interchangeable manufacturing tolerance analysis is required while inspection of parts.
• There should also be properties evaluation and geometrical evaluations in Area, Volume, and property evaluation in Weight, Density, etc..
• Need for Finite element analysis and Kinematic analysis.
• Parts classification, planning, etc. in manufacturing.

Geometric modeling is a vast and elaborate field of CAE and requires in-depth study. The next articles dive deep into the various types and facets of geometric modeling.

### The New Product Development Process

You might be a seasoned design professional thinking “What do my bosses sit around and do all day while I do the real design work".

This section outlines and explores the various early stages of the industrial design process that a product goes through. It does serve as a reasonable account of the overall and general product design process.

• ##### Ideating or initial ideas

Before any design work can begin on a product, there must first be a definition of what the product or product line might be. The idea’s genesis can be many factors such as:

Consumer demand – Reviews & feedbacks from the customers or even their ideas can help companies generate new product ideas.

Internal sources – Companies provide incentives and perks to employees who come up with new product ideas

Market research – Companies constantly review the changing needs, requirements and trends of the market by conducting plethora of market research analysis.

Competition – Competitors SWOT analysis helps companies to generate ideas.

• ##### Idea screening

An idea can be excellent, good, moderate or very bad. Once a suitable product opportunity has been identified, a specification document or design brief is created to define the product. It is usually created by the higher management of a company who’ll have access to information, such as budgeting and buyer/seller feedback. This step involves filtering out the good and feasible ideas which maintains the technical integrity while staying within realistic cost expectations.

Features such as a mechanical specification or a reference to an existing invention the product might be based upon, are outlined. Expectations, uses, and underlying intelligence associated to the product are included as well. Electronics, including sounds, lights, sensors, and any other specific inputs, such as colors and new materials may also be mentioned. Finally, a few reference sketches or photo images can be added to convey a possible direction.

• ##### Concept design & development

All ideas that pass through the screening stage are turned into concepts for testing purpose. A concept is a detailed strategy or blueprint version of the idea. In most companies, designers work up a design brief or product specification that guides their designs. It’s the designer’s role to make these ideas a reality. A professional designer has the ability to provide a large variety of designs in a quick and efficient manner. Many people can draw one or two ideas, but when asked to elaborate they often fall short. What separates the true design professional is depth and breadth of their presented ideas and vision in a clear and concise manner. Concept design generally means the use of hand-drawn or digital sketches to convey what’s in a designer’s mind onto paper or a screen.

A detailed business analysis is required to determine the feasibility of the product. This stage determines whether the product is commercially profitable or not, whether it will have a regular or seasonal demand and the possibilities of it being in the market for the long run.

• ##### Modeling

With the help of 3D modeling software (CAD – Computer Aided Design), the ideas/concept is rendered a shape, thereby creating a 3D model. The technical and engineering team has the biggest workload during this phase. These 3D models will often show up problematic areas where the theoretical stresses and strains on the product to be developed will be exposed. If any problem persists, it is a best phase of product development to handle the design errors and come up with modifications to address the same.

• ##### Prototyping & pilot runs (preliminary design stage)

In this stage, prototypes are built and tested after several iterations and pilot run of the manufacturing process is conducted. This stage involves creating rapid prototypes for a concept that has been deemed to have business relevance and value. Prototype means a ‘quick and dirty’ model rather than a refined one that will be tested and marketed later on. Adjustments are carried out as required before finalizing the design.

• ##### Test marketing

Apart from continuously testing the product for performance, market testing is also carried out to check the acceptability of the product in the defined market and customer group. It is usually performed by introducing the new product on a very small scale, to check if there are any shortcomings. This helps to know in advance, whether customer will accept and buy this product on launching in the market. Test marketing is a powerful tool indeed.

• ##### New product launch

This is the final stage in which the product is introduced to the target market. Production starts at a relatively low level of volume as the company develops confidence in its abilities to execute production consistently and marketing abilities to sell the product. Product manufacturing expenses depend on the density of the product, if there are numerous parts, material selection etc. The organization must equip its sales and customer service entities to address and handle queries. Product advertisements, website pages, press releases, and e-mail communications are kept on standby on the launching day.

Product development is an ever evolving fluid process and cannot be summed up in a few steps. The entire procedure sees insertion of additional stages or even eviction of a crucial part, depending on the nature of the project. Each group of professionals, whether designers, engineers or marketing, sales; has their role to play in this methodology. It is the company’s responsibility to continuously monitor the performance of the new product.