What is optimization?Optimization is the process of modifying a system to make some aspect of it work more efficiently or use fewer resources. Design optimization is the application of numerical algorithms and techniques to engineering systems to assist the designers in improving the system's performance, weight, reliability, and/or cost.

Most engineering systems have a very large numbers of variables, and designers have to specify appropriate values for these variables. However, because of the size and complexity of a typical design task, even the most skilled designer cannot always take into account all of the variables simultaneously. This is where design optimization plays a useful role.

You can apply optimization methods during the product development stage to ensure that the finished design has high performance, high reliability, low weight, and/or low cost. Alternatively, you can also apply optimization methods to existing products to identify potential design improvements.

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Optimize the center of gravity

In this activity, you will:• Optimize a model based on a target value CG using variable limits.• Review associative measurements.

Applications:• Component placement• Design feature sizing

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Optimize the center of gravity

To get started:1. Download and Open exp3_drive_hub in NX. ‘Save as…’ a copy to

allow editing. 2. View the ‘Expressions’ (‘Tools’ → ‘Expressions’ tab or Ctrl+E)3. Investigate how changing the ‘left_rev’ and ‘right_rev’ values

affects the model, and how shifting these parameters might move the body’s center of gravity (CG).

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Optimize the center of gravity

To get started:1. Download and Open exp3_drive_hub in NX.

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Optimize the center of gravity

Create a distance measurement expression :

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Optimize the center of gravity

Rename the distance measurement expression :

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Optimize the center of gravity

Set the study name and objectives:

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Optimize the center of gravity

Define the design variables:

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Optimize the center of gravity

Set the algorithm and run the studies:

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Optimize the center of gravity

Review the results of the optimization:

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Optimize surface area by varying pin spacing

In this activity, you will:• optimize the model in order to find the suitable pin spacing values to

achieve the surface area requirements.

Applications:• Solar panel / radiator configurations• Rib / stringer optimization (replace surface area with cross sectional

area, viola!)

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Optimize surface area by varying pin spacing

1. Open exp3_air_flow: 1(a) (optional) Open the ‘Expressions’ tool (Ctrl + E) –See how changing the ‘diameter’ and ‘spacing’ expressions affects the model.

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Optimize surface area by varying pin spacing

Define the variables:

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Optimize surface area by varying pin spacing

Define the algorithm and run the study:

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Optimize surface area by varying pin spacing

Review the results of the optimization:

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Sensitivity Study

• A Sensitivity study differs from an Optimization study in that the Sensitivity study generates a list of all possible design improvements, while the Optimization study generates a single, best solution for your design.

• Use the Sensitivity Study command to browse the design space of any given parametric model to test its robustness and performance on a given set of input parameters.

• The command lets you carry out a variety of systematic studies performed as part of the design process in an attempt to understand the effect of design variables on required outcomes. You can vary one or more model parameters over specified ranges to observe the effect on model performance and to evaluate design trade-offs.

• Sensitivity study results can be used in robustness analysis and identifying design alternatives that are less susceptible to variation in the design inputs.

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Sensitivity study

In this activity, you will: • examine a design for a ballast weight for a sailboat.

To do this you will run a Sensitivity study to determine which characteristics have the greatest impact on the final mass. You will also identify some specific design sizes that come close to the optimum solution.

Applications : Literally everything in a complex system

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Sensitivity study

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Sensitivity study

1. Open exp3_sailboat_ballast:

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Sensitivity study

Name the study and define the variables:

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Sensitivity study

Define the watch variables:

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Sensitivity study

Establish settings and run the study:

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Sensitivity studyExamine the results spreadsheet:

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Sensitivity studyExamine the results:

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