It's summer*, which means there's a gang of interns roaming the halls here. It's nice to have some young people around, which makes me feel increasingly old at the ripe age of 33. One of the great things about college students is that they think of stuff that you never would.
So when I was asking my intern to come up with some interesting things for our Facebook page a little while ago, he mentioned something about SolidWorks graffiti. To be honest, I didn't really understand what he meant. So imagine my surprise when, three minutes after leaving my office, I get this in my inbox:
Copyright Josh Harris
So that's what he meant. Never in a hundred years would I have though that someone would do something like this, but I think it's pretty cool nonetheless.
What other unorthodox usages of SolidWorks (or any other CAD software for that matter) have you seen?
* Here in Massachusetts, it'e summer in name only. I don't think the mercury has risen above 80 degrees fahrenheit the entire month.
Last week I told you how to check your global mesh refinement by performing a number of simulations with a denser mesh and looking for convergence of your results. Have you given it a go yet?
This week we held a 2 day simulation training session covering the topics of motion and non-linear studies for our resellers and one of the surprising things for a lot of people was the sensitivity of the results to various parameters. The motion studies were highly sensitive to the contact settings and a non-linear buckling analysis we ran was very dependent on the mesh size chosen.
When discussing the implications of this it became clear to everyone that building a simulation, solving it and immediately believing the result can be a dangerous pastime. We call this ‘one-shot’ approach an Absolute Analysis, giving one absolute answer.
But what would you say if I asked how certain you are of your input loads? Could they be, say 5-10% out? Also, have you modelled all the boundary conditions accurately or used an approximation, perhaps fixing a face when in reality it is bolted to a plate? Have you chosen the true material data or an approximation from the database simply because it is there?
To mitigate these cumulative errors it is better to perform a Relative Analysis, a series of simulations where you change each parameter to see how it impacts the result.
If you are not sure that your loading is exactly 500N, try one at 450N and another at 550N. Is the direction of the loading really normal to the face of application? Perhaps you could check the result by running a couple of simulations with the load offset at 5 degrees each way to see how the induced moment affects your design. Using a bolt connection and a no penetration contact will give you a different result to a fixed restraint so try it to see just how different the results are. And finally perform a few studies with slightly varying material properties to see what impact this has.
The power of this approach is similar to the convergence check, you are making sure that your model is robust, i.e. not sensitive to variation, and if it is, you can begin to determine just how sensitive. This approach is also one way of building a real understanding of your product so you can appreciate how it behaves in the non-ideal world we actually live in.
For those of you who are looking up and down the supply chain for ways to improve environmental performance – and save yourselves literally millions in the process, discover SustainabilityXpress.
Our new sustainability software package code-named “Sage” will be available with the release of SolidWorks 2010.
Have a look at the video on SolidWorks Lab. Be the first one to review the product.
Confused by all the buzzwords surrounding design and sustainability?
There are indeed a lot of buzzwords surrounding sustainable design today. Much of the debate surrounding environmentally friendly product design and manufacture hangs on the question of costs and profits: can I afford to go green?
As if reducing materials, designing more efficient manufacturing techniques and technologies, using less energy in production, spending less on raw materials and finding ways to reuse components and materials would actually cost more. What is Design and Manufacture all about? Isn’t it all about creating the maximum possible value with minimum resources?
So, assuming as product designers and manufacturers we are already taking steps to make the best use of the resources we have, the question should be not: can I afford to go green? But rather: just how green is it possible for me to get?
See what people are saying about the issues on DesignTalks and add your voice to the debate.
This week I gave an overview of some simulation best practices to some of our Nordic partners, and I thought I’d share one of their tips with you this week.
How do you know if your mesh is sufficiently refined? There are a number of checks and balances that can be used to assess the quality of your mesh in particular areas, but what about the general level of mesh refinement? One under-utilised technique is the convergence check.
Firstly create an initial mesh on your model and plot the number of degrees of freedom (DoF) against a result of interest (e.g. max displacement). Then remesh with a finer mesh (try to at least double the DoF in your second attempt) and again plot the result of interest. Keep doing this until you see the resultant parameter converge to a solution. When you are happy you have a converged result, you will also have a suitable global mesh.
Two additional points to think of:
if you choose stress as your function of interest ensure you don’t have a stress concentrating region in your model, otherwise you will find the value increasing indefinitely.
if your ‘ideal’ mesh takes forever to solve, you can pick a courser mesh size from the graph that solves quicker and gives you an understanding of the error when compared to the converged solution. If 160,000 DoF takes too long but the result at 80,000 DoF is within 5% error, this may be sufficient.
Back in March Jeff Ray wrote the blog article ‘Why Amazon Will Save the World’ which talked about the Amazon Kindle. Since reading that article I had toyed with the idea of purchasing an ‘electronic book reader’ but paused when I read that a newer model of the Kindle would be available soon. The Kindle 2 soon became available but then I balked at the price for a device that only allowed me to read books.
Recently I took a trip where I endured a four hour airport layover. I browsed the ‘electronic gadget’ store where the Sony Reader was being promoted and I thought; an electronic book reader would sure be handy now.
But, what to buy? I ended up buying the Sony Reader because it could store PDF files (and I wanted to store my vast library of EPDM Tech Tips) and because I got a really good deal price-wise.
Huh? I have a netbook that I take with me everywhere outside of the office. I like the small size and the fact that I can read my email, browse the web and keep up with social networking sites. Turns out my netbook is perfect for carrying around my library of PDF documents! Additionally, you can install Adobe Digital Editions or Sony eBook Library software and download eBooks.
Possible caveats might be eye strain that reader technology minimizes. Also, I have found that the Kindle offers access (via the Amazon book store) to more book titles at better prices.
In closing, figure out how you want to use your reader and choose the best option for your needs.
SolidWorks 2010 beta isn't the only thing going live next week. In a few short days, you'll be able to get your hands on a beta version of SolidWorks Sustainability Xpress, the product we announced at SolidWorks World 2009 under the code name Sage. It'll be available for download on the SolidWorks Labs site. Until then, here's a quick look at what you'll get. Director of Product Innovation Rick Chin was nice enough to take a few minutes and give me a quick run-through. Enjoy!
Every year we give our customers a chance to preview the newest release of our software before it's made available to the public, and this year is no different. In the very near future, we'll be making the beta version of SolidWorks 2010 available for download to current subscription support customers in the SolidWorks Customer Portal.
You'll have all summer to play with the software, see what's new, and generally get an idea of what to expect when it's finally baked. If you want, you can even let us know if you find bugs or other problems. Find enough and submit them through the system and you can even win prizes. If you want to get a peek at what new features you can expect to see, click here to read the list Ricky Jordan posted on the last day of SolidWorks World 2009.
If you've already signed up to be notified when the beta program starts, be on the lookout for an email soon. If not, drop everything, click on this link, and sign up. We look forward to seeing you.
Last week I posted about our 2010 beta program. I've gotten confirmation that we're going live next week. Let the testing begin!
If
you've already signed up to be notified when the beta program starts,
be on the lookout for an email soon. If not, drop everything, click on this link, and sign up. We look forward to seeing you.
That's all. Until tomorrow, anyway. I have something exciting to show everyone.
Over four million children die each year before their first
month of life; 99% of them in developing countries. For those of you who joined
us at SolidWorks World this year (or watched the videos), you’ll recall us
recognizing local nonprofit Design That Matters for
tackling this problem with an incubator designed specifically for the needs of
developing nations.
Well, DtM isn’t resting on its laurels; the engineering and
design students have taken on the next phase, providing a low-cost, low-maintenance respiration
device for “thermoregulation” using CPAP (Continuous Positive Air
Pressure). This will help premature and low birth weight infants with
respiratory distress.
I’ll let you go to their website to learn more about the
medical condition – I’ve already exceeded the limits of my medical know-how.
So, let’s look at the winning design, as presented by a cross-functional team of students
from the MIT school of Engineering, the Sloan Graduate school, and the Rhode Island School of Design.
I was lucky enough to attend their final presentation and
was blown away by the team’s resourcefulness and problem-solving skills. Now,
these are students from very different backgrounds and disciplines, all thrown
together to attack this one problem against a strict deadline (the grading
cycle). So seeing them learn how to work together was fascinating. But the
design was cool. Most respirators cost from $2,500 - $9,000 and require lots of
training and expensive parts.
This device (shown above) had one moving part, and made clever use of
off-the-shelf products to save cost and complexity. It ended up coming in under
$600, and did all the important things of the fancy machines. The user
interface got the same attention as the device itself, with no words and simple
“happy face” and "sad face" pictures for three lights. There were three design goals:
affordability, intuitive UI, and the ability to be locally-maintained. The DtM students went
three for three!
What do we get out of this? Thousands of lives saved, and
the next generation of engineers and designers who are inspired to make this
world a little better. What a great time to be an engineer!
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