31-1-2016
Performance based
parameterization strategies
A theoretic framework and case studies
Performance oriented parametric modeling
• Performance oriented design uses performance evaluations to drive the design choices Architectural performances are affected by geometry
Early integrating performance evaluations of geometric design alternatives is crucial • Parametric modelling supports early integrating performance evaluations
It represents both geometric entities and their relationships
Relationships are structured in hierarchical dependencies, including independent parameters Variations of independent parameters generate different configurations
Instances of the model can be explored with respect to a given set of design criteria
Potentials
• Possibility of generating design alternatives
• Once meaningful geometric associations have been embedded in a parametric structure, the structure can be re-used in future models
Challenges
• Parameterization strategies are crucial to define meaningful solution spaces
• Since systematic performance evaluations are not possible for the entire solution space, properly selecting the solutions to be evaluated is crucial
• Strategy-definition: formulation of parameterization strategies.
• Given a design concept (primary generator), preliminary numeric analysis allow understanding challenges and potentials to fulfill the design requirements
• Specific sub-goals are established, which decompose the design requirements into more specific tasks
• Various design aspects are analyzed to identify a list of design properties impacting the achievement of the sub-goals
• For the aspects having positive impact on the goals, geometric properties are extracted and their attributes are parameterized
• Model-building: construction of parametric model according to the logic emerged in the first phase
• Solution-assessment: exploration of the parametric design alternatives based on performance evaluations
• The three phases are interrelate with each other.
• Interrelations between strategy-definition phase and solution-assessment phase are
particularly important, especially regarding meaningfulness and breath of solution space. • The more knowledge is available during strategy-definition, the more the actual solution
space can be made to coincide with the desired design solution space and the need for analyses during solution-assessment can be reduced.
• 3 case studies
Case study 1: large solution spaces
Primary generator
Parameterization of geometric attributes
1F-Strategy-definition:
2F-Model-building:
GENERATE
BREED
STORE EVALUATE
3F-Solution assessment. Search algorithms
Example with GAs
Case study 2: narrowed solution spaces
Daniel Van Kersbergen,
Schiphol Interchange Station - Integrated design research for the
wind and daylight performance of the building envelope
, Turrin, Heinzelmann, Cuperus, Mentors; MSc Thesis 2011, TUDelftDesign Requirements
DAYLIGHT Daniel Van Kersbergen
1F-Strategy-definition. Acquiring knowledge
PRELIMINARY ANAYSIS: DIGITAL SIMULATIONS ON MODELS
PRELIMINARY ANAYSIS: PICTURES WITH SPECIAL CAMERA*
*Konica Minolta’s T-10 series. The T-10 and T10M are used to measure the illumination strength in the tests. The T-10 is used for standard illuminance measurements (exterior) and the T-10M for small-surface illuminance measurements (interior).
2F-Model-building. Limited parametric values
FINAL ANAYSIS: DIGITAL SIMULATIONS ON DETAILED MODELS
3F-Solution assessment: satisfactory performance
The geometric configuration and the materials chosen by the student to run the first analyses were assessed as relevantly close to satisfactory for the desired performance
This shows how relevant a deep preliminary analysis phase is in order to meaningfully narrow the parametric solutions space to be further explored.
Case study 3: deterministic solution spaces
Foteini Setaki,
Acoustics by additive manufacturing
, Turrin, van Timmeren, Tenpierik, Mentors. MSc Thesis 2012, TUDelft1F-Strategy definition. Mathematic formulation
The primary generator was defined by the student only after the strategy-definition phase was finalized. This consisted of a relevant number of tests, which included conception and 3D-printing production of different prototypes embedding a number of geometric variations to study their impact on sound absorption.
3F-Solution assessment. Guaranteed goodness
Only when clear principles were formulated, the primary generator was conceived and its parameterization process finalized upon the principles extracted during the tests.
Parameters:
• length of the air-paths • diameter of the air-paths
Guarantee of good performance is expected from the instances of the parametric model. The model acts in this case as generic design tool applicable in future projects, to parametrically generate different design solutions according to different acoustic conditions.
Conclusions
• The first case study focusses on large solution spaces and computational supports for exploration
• The second case study focussed on increased performance analysis during strategy-definition in order to increase the correspondence between the actual and desired solution spaces. It has shown how relevant a deep preliminary analysis phase is in order to meaningfully narrow the parametric solutions space to be further explored.
• The third case study focussed on the full coincidence between the actual and the desired solution space, based on deterministic relations between geometry and performances. The choice the designer makes concerning the time and effort investment during the different phases and the awareness concerning the consequences of the attitude taken at the different phases of the process are essential.
