What is Parametric Modelling?
Parametric modeling is a design approach that uses logic, algorithms and rules to define geometry and properties. This means, instead of manually drafting each part of a model, designers establish a set of inputs, rules and constraints that drive the design. This approach allows for flexibility, efficiency, and iterative improvements, making it especially useful in architecture, engineering, and product design.
At its core, parametric modelling involves defining input parameters, such as dimensions, angles, and materials, and establishing relationships between them. When one parameter changes, the entire model updates accordingly, ensuring consistency and responsiveness throughout the design process.
Parametric modelling and tools such as Rhino3D and Dynamo have gathered a lot of momentum in the past decade in the Architectural, Engineering and Construction space, not only as a way to define geometry but also as an effective way to manage and manipulate data. Here, we will talk mainly about parametric modelling in the Structural Engineering space.
The Parametric Modelling Workflow
The parametric modelling workflow follows a structured process that integrates geometry creation, structural properties, analysis, design and optimisation. The diagram below illustrates this workflow, which can be broken down into several key steps:
1. Conceive Design
The first step in parametric modelling is defining the overall design intent. This involves conceptualising the structure and setting high-level goals, such as material efficiency, aesthetic preferences, or performance criteria.
2. Define Input Parameters and Relationships
Once the concept is established, input parameters and relationships are defined. These parameters may include:
- Geometric dimensions (length, width, height)
- Material properties
- Structural loads and constraints
By establishing these relationships, the design remains adaptable. If one parameter changes, all dependent elements adjust accordingly, allowing for seamless modifications.
3. Generate Geometry
With the parameters set, the model generates the geometry based on predefined rules. This stage involves creating shapes, surfaces, and forms that adhere to the constraints established in the previous step. Since geometry is rule-based, multiple design iterations can be explored quickly by adjusting the input values.
Incorporating Structural Properties and Analysis
Parametric modelling extends beyond simple geometry creation; it allows for the integration of structural properties and engineering analysis to ensure designs are both functional and efficient.
4. Assign Structural Properties
Once the geometry is generated, structural properties such as material strength, load-bearing capacity, and stiffness are assigned to different elements. This step ensures that the design can withstand real-world forces and constraints.
5. Perform Structural Analysis and Design
With structural properties in place, engineers perform structural analysis to evaluate the performance of the design under different conditions. This step may involve:
- Load testing
- Stress and strain analysis
- Finite element analysis (FEA)
By incorporating structural analysis directly into the parametric model, adjustments can be made in real-time to improve the design’s integrity and efficiency.
Optimisation in Parametric Modelling
Optimisation plays a crucial role in parametric modelling, allowing designers to explore the best possible configurations based on specific goals. The diagram highlights two key types of optimisation:
6. Topology Optimisation
Topology optimisation is a process that refines the design by removing unnecessary material while maintaining structural integrity. By linking back to the input parameters and geometric relationships, this iterative approach results in highly efficient, lightweight structures.
7. Design Optimisation
Design optimisation fine-tunes parameters such as material selection, shape, and dimensions to achieve optimal performance. Whether the goal is to reduce material usage, improve aerodynamics, or enhance strength, parametric modelling enables rapid testing of multiple variations.
The Outcome: A Refined Design
Through this structured workflow, parametric modelling leads to a well-optimised design that meets functional, structural, and aesthetic requirements. By integrating parameter-driven geometry, structural analysis, and optimisation techniques, designers and engineers can create smarter, more efficient, and adaptive solutions.
Conclusion
Parametric modelling revolutionises the way we design by introducing flexibility, efficiency, and intelligence into the workflow. By defining input parameters, generating geometry, and incorporating structural analysis and optimisation, designers can develop solutions that are not only innovative but also highly functional. As computational tools continue to evolve, parametric modelling will remain at the forefront of design and engineering, shaping the future of architecture, manufacturing, and construction.