1: Definition and history of CAD

Definition and History of CAD

Definition
Computer-Aided Design (CAD) refers to the use of computer software to create, modify, analyze, and optimize designs for physical components or systems. It replaces manual drafting with digital tools, enabling precise 2D drawings and 3D models that define geometry, dimensions, materials, and manufacturing constraints. CAD systems automate design tasks, enhance accuracy, and facilitate collaboration across engineering disciplines.

Historical Development

• 1950s–1960s: Origins
  CAD emerged from early computer graphics research. In 1957, PRONTO, the first numerical control programming tool by Dr. Patrick Hanratty, laid groundwork. Ivan Sutherland’s Sketchpad (1963) pioneered interactive graphics, introducing concepts like object snapping and constraints.

• 1970s: Commercialization
  Mainframe-based CAD systems like CADAM (Lockheed) and CATIA (Dassault) dominated aerospace and automotive industries. These tools focused on 2D drafting and basic 3D wireframe modeling, drastically reducing design time but requiring costly hardware.

• 1980s: Rise of 3D and Personal Computers
  Solid modeling gained traction with systems like Romulus (ShapeData) and Unigraphics. The 1982 launch of AutoCAD revolutionized accessibility by bringing CAD to PCs. Key innovations included boundary representation (B-rep) and constructive solid geometry (CSG), enabling realistic 3D part visualization.

• 1990s: Parametric and Feature-Based Design
  Parametric modeling reshaped CAD workflows. Pro/ENGINEER (1987, released widely in the 1990s) linked dimensions to geometry, allowing automatic updates when parameters changed. This era also integrated CAD with analysis (CAE) and manufacturing (CAM), forming the foundation of product lifecycle management (PLM).

• 2000s–Present: Integration and Democratization
  Cloud-based CAD (e.g., Onshape) enabled real-time collaboration. Direct modeling tools like SpaceClaim offered flexibility for complex edits. Modern AI-driven features automate tasks (e.g., generative design), while additive manufacturing compatibility supports rapid prototyping. Open standards (e.g., STEP files) ensure cross-platform interoperability.

Impact
CAD evolved from simple drafting aids to comprehensive digital prototyping environments. It accelerated design cycles, reduced errors via simulation, and became indispensable in industries from microelectronics to civil engineering. Future trends emphasize AI, virtual reality integration, and sustainable design optimization.