5 Traps to Avoid When Using Simulation for Product Development

When implemented correctly, simulation can bring many benefits to your product

development. However, you need the right processes or you can wind up reducing the

value or providing a false sense of security. Here are the top five traps to avoid.

1. Failure to Understand the Physics

One common danger is failing to understand the underlying physics of your application.

Software cannot do all the thinking for you - if you don't understand the fundamentals

then disaster awaits.

The allure to play around with phenomena you don't fully comprehend is tempting. I

have a vivid recollection of an engineering team that believed that they had conceived a

revolutionary flow accelerator that would radically change how we capture wind energy.

Unfortunately, they were using an incompressible fluid assumption in their CFD code to

model supersonic flow. Let's just say that breaking the news to them was ….

uncomfortable.

2. Going in Blind

Another snare is that some people expect simulation to provide predictive results of

complex phenomena without experimental benchmarking or material testing. While

simulation can provide valuable information about general trends, detailed

experimentation is still key to achieve its true potential as a predictive tool.

Figure 1: Benefits of Simulating Early and Often

Product development teams have to make the initial investment in time and energy to

carefully verify and validate the simulation method for each unique process to which it

will be applied.

3. Waiting to Simulate

Perhaps the biggest mistake is to wait until the design is complete before simulating. If

simulation is only performed late in the design cycle then it is almost not worth doing.

Instead of accelerating the process, it actually delays the design process. You may as

well take your chances with a prototype test and hope for the best. This is the main

reason you hear the common cry: "I don't have time to simulate!"

On the other hand, simulating throughout the entire design process maximizes the

benefits at the conceptual stage. This will drive innovation, provide guidance, allow for

quick vetting of concepts, and help to avoid a late stage blind side. If performed

properly, the final analysis becomes merely a confirmation. This strategy helps

compress as well as define the entire process.

4. Failing to Plan

Don't forget to allocate enough time and resources for simulation when planning out the

development schedule. While serving to ultimately compress the design cycle, it should

come as no surprise that simulation requires manpower. Unless this allocation is

prepared at the outset of the project you will likely never touch the software.

If design and simulation are performed by different groups then it is also important to

collaborate closely. Teams need to adhere to timelines drawn up during the planning

stages. In this way, it will be less likely that simulation will be abandoned if schedules

begin to slip.

5. Assuming You Know Everything

One final trap to be aware of is failing to incorporate uncertainties as part of the

simulation process. The real world is uncertain; nothing is manufactured with all

dimensions being "nominal." The analysis of one geometric configuration, using one set

of loads, material properties, and boundary conditions barely scratches the surface.

Figure 2: Assessing the effect of geometry changes 

on component life

To perform simulation in this manner is very limiting. In the best case, you risk over-

design because you need to be overly conservative. In the worst case, you experience an

unacceptable rate of in-service failures.

Simulation is critical for analyzing multiple variants of a design.

With the right design process, software tools and hardware option, it is relatively easy

to analyze multiple variations of the same design. Doing so will help you gain true

insight into the effects of uncertainties. Failure to do this will put you at a competitive

disadvantage.

Avoiding these five common traps will go a long way to ensuring your organization will

perform simulations effectively and achieve all the benefits that it has to offer.

How SolidWorks Simulation Helps Simulation at Design

No one is going to tell you thatSolidWorks Simulation is a simulation

powerhouse; it isn’t trying to be. The key to the software’s success isn’t eye

popping feats like multiphysics, high cell counts, adjunct solvers, or fancy

meshing tools seen in COMSOL, STAR-CCM+, ANSYS, and Simulia. SolidWorks

Simulation instead brings the power of simulation into a CAD environment and

therefore the initial design stages. This offers simple, cheap, quick methods for

designers and design engineers to make more informed early decisions

producing an overall more optimized product. After all, sometimes it’s David

that really beats Goliath.

Simulation Early in Design

“When analysis started hitting the mainstream in the 80’s, it was something done at the

end of the process,” said SolidWorks Simulation expert Glenn Whyte, a Simulation

Product Manager at Hawk Ridge Systems. “You build the plane at Boeing and just

before your flight you run an analysis that was pass or fail. Pass you are good to go; fail

you move right back to the start again.”

Simulation at the start of the design process, however, means that you are able to test

every decision along the development cycle. Design engineers are no longer over

engineering a piece to ensure it passes the analyst’s muster. Instead through quick

guess and check, they are optimizing the material, manufacturing process, cost, and

even environmental impact by performing simple simulations.

What the Program Can Do

Depiction of Simulation Program’s complexity and target users as described by Glenn

Whyte.

“We look in the industry and see differences in expertise requirements from designers,

to design engineers, to full time simulation engineers and pure analysts. We see

SolidWorks as a design to engineering tool. One of the main advantages of it is that it is

integrated into CAD during the design workflow. This will shorten the learning curve.

We explain to our customers that have never done analysis before that they can analyze

4-5 different scenarios in an hour. Just by manipulating the CAD, processing the

analysis, and keeping track of what those changes mean physically. Simulations are also

completely integrated with the CAD model, if you make a design change then it is ready

to analyze without intermediate steps like file exporting. It will also use the existing

mesh settings to re-mesh the model,” said Whyte.

Chart automatically keeps track of the optimization after every simulation.

He wasn’t exaggerating. During a live demo two engineers in training, with little

experience in SolidWorks Simulation, were able to run about a dozen simulations each

in an optimization challenge. Having applied their knowledge of the CAD environment

they were able to optimize the safety factor of a camera mount by limiting the mass of

the mounting panel. Meanwhile, a chart kept track of results of each simulation run.

Whyte said that SolidWorks Simulation “goes into some fair depth like non-linear

dynamic analysis and it has a very capable CFD tool. We can draw different

stratification for CFD and see how things will stack up differently. But when you go into

highly non-linear, multiphysics, and highly dynamic problems we get close to the limit of

our solver’s abilities. This is when you pick up ABAQUS, LS-Dyna, or Marc”

He has a fair point. It doesn’t make sense to run a simple problem in more complicated

simulation programs. Setting up the program, exporting the files and fixing the

geometry can take hours before you even run the simulation. In SolidWorks it will take

no more than 5 minutes. Additionally, subsequent simulation set up is as simple as

altering the CAD model.

“There is a productivity boost,” said Whyte. “If you are doing an analysis that fits in the

assumptions made by the linear static stress analysis, which is 80% of the analysis done

out there today, tools like the analysis capabilities we have in SolidWorks Premium are

the most productive way to get a result, and our Simulation Professional and Simulation

Premium packages can then take you a little further.”

No Frills Means Easy to Use“Our developers have made a conscious decision to utilize easy to mesh element types and algorithms. We have five different mesh elements we can use but most solid body analysis is done with tetrahedrons. They get good results in most situations and they are very easy to write meshing algorithms for … We also retain control with adaptive meshing techniques where the mesh will change dependent on the stress gradients,” said Whyte.

Additionally, tools like linked multiphysics can certainly ensure

that the final designs are completely optimized for final users. However, setting up such

an analysis can take time and skills of a full simulation analyst.

Eliminating these tools may hurt the ability to completely optimize the problem but they

are necessary to ensure designers and design engineers can use simulation properly.

Besides, these “frills” fulfill a task much farther down the development cycle than initial

design. At the initial design stages performing separate quick and easy physics

simulations can be useful to limit the final designs destined for analysts to a short list

saving time and money.

Make sure you buy the Right Thing!

As seen in the chart below, perhaps the most confusing thing about the SolidWorks

packages is the naming convention. Though Dassault Systemes’ top design tool

SolidWorks Premium does include simulation, it is the basic version which only includes

linear static simulations in assemblies and time based motion simulations.

However, this package can be extended with additional analysis types available in

SolidWorks Simulation Professional and SolidWorks Simulation Premium, like fatigue,

frequency, nonlinear and dynamic analysis.

Product Matrix. Be careful with the odd naming conventions.

AnalysisSolidWorks

Premium

SolidWorks Simulation

Professional

SolidWorks Simulation Premium

SolidWorks Flow Simulation

Static Stress X X X

Time-Based Kinematics

X X X

AnalysisSolidWorks

Premium

SolidWorks Simulation

Professional

SolidWorks Simulation Premium

SolidWorks Flow Simulation

Event-Based Kinematics

X X

Optimization X X

Thermal X X

Sub Modeling X X

Fatigue X X

Frequency (simple vibration)

X X

Buckling X

Pressure Vessel X X

Drop Test X X

Composite Materials

X

Nonlinear X

Random Vibration X

Dynamic X

Rotating Machinery

X

Heat Transfer & Cooling

X

Flow (Internal & External)

X

“There are three other simulation technologies,” explains Whyte. “Flow Simulation is a

CFD tool used for fluid flow and heat transfer. It has some extensions for electronics,

and the HVAC industry. We also have a simple first pass life cycle assessment tool to

determine the environmental impact of the materials and manufacturing choices.

Finally, we have a plastic injection molding tool to detect potential injection molding

defects … Generally we don’t like to bundle things. Typically you want to be able to buy

what you want.”

However, Whyte was quick to note that the other benefit is cost: “though only a sales

team can give you a final quote, you can get SolidWorks Simulation at a fraction of the

cost of other simulation tools.” This means companies can reduce the licenses of other

costly heavy lifting simulation tools, which are far too advanced for designers anyway,

and limiting those licenses to analysts and simulation engineers. This can ensure

designers are able to perform simple simulations on a lower budget.

Conclusion

Again, SolidWorks Simulation isn’t the tool for complicated high level simulations. But

that weakness has been turned into a strength. This barebones simulation tool will

ensure that your designers and design engineers will pass on fewer partly optimized

designs to analysts and simulation engineers.