Keymark Blog

Angry Birds is a puzzle game developed by Rovio wherein angry looking birds are positioned on a slingshot and launched at pigs resting in different structures. The back-story is that the pigs have supposedly stolen the birds’ eggs, instigating the attacks. The gaming idea is simple: fire the bird, destroy the evil pigs’ headquarters and retrieve the egg. The structures on which the pigs reside are made of different materials including wood, concrete, glass, and even snow. I’ve played this game for a year, progressing ever deeper into the levels and versions. While it is fun to knock out all the snidely grunting pigs (they smirk arrogantly if you fail a level and have to repeat), I feel even more profound satisfaction when I completely and utterly destroy their structure.

I decided, in a lucid moment after the pig-slamming frenzy wore off, to look at how the Angry Birds structures are assembled, and various strategies for annihilating them with my birds. For example, here is a simple level with a simple structure of beams and columns stacked on top of each other, with a heavy rock weight positioned above the hapless pigs. Wood is brown, stone is grey, and glass is blue. A direct-attack strategy results in nudging the structure sideways and blasting some of the pigs, but the well-positioned boulder is wasted as a weapon and we are left with the lowest pig in a well-protected position. (Click images to play videos.)

A better strategy is to identify the glass beams as a critical weak link in the structure. Glass is a brittle material that shatters when loaded in the longitudinal direction. If we aim our bird just right, we will impart an axial compression load on the glass beam. This is the key to utter destruction.

The makers of Angry Birds exploit these structures in the extreme. Below are some examples of extreme levels. Can you find any critical links in these systems? Hint: If you approach the problem like a structural engineer, you will often find that taking out a piece of foundation allows the structure above to come crashing down. (Click images to play videos.)

Here is one level that baffled me until my 8-year-old son took a turn. He attacked the middle of the pile of glass balls, and always the pigs at the bottom were hard to reach. Then, he noticed the leg on the right wall near the bottom pig was tilted. He aimed his bomber bird to explode such that the force of the explosion nudges the tilted leg just a bit. Voila! Bye-bye piggies. (Click images to play videos.)

The handful of examples I have selected is just the start. The makers of Angry Birds have added many variations to keep the game interesting. For example, certain birds are more effective against certain materials than others and some birds have special powers. Sometimes the pigs have multiple levels of structural protection, and their protection is static or mobile. In Rovio’s most recent version, Angry Birds Space, they have added new variations for the mechanical effects of gravity on the catapulted birds.

In the future, if there is enough interest from readers, I will attempt to catalog the creatures, materials, structures, and strategies in the Angry Birds universe. Are you an Angry Birds fan? Are you willing to share any of your personal strategies to playing the game? What structural weaknesses have you found to destroy the pigs?

Examples of Extreme Structures:

Johnny Drozdek, Structural Engineer and Angry Birds Fanatic!

I love wood. I love structures built from wood. When I was in college and grad school I daydreamed about becoming a structural designer of timber bridges. Exposed wood materials can be attractive and add warmth and natural vitality to a structure. Wood is versatile and can be formed into many shapes. It is lighter and easier to work with than other structural materials such as concrete or steel, and it can be used in most climates to perform virtually any structural purpose.

I recently read an article about a 30-story skyscraper in Vancouver that is planned to be constructed completely out of wood. This is being touted as perhaps the world’s tallest wood-frame structure. Reading through the arguments in favor of tall wood buildings, I learned that the production of concrete might account for as much as 5 percent of the world carbon dioxide emissions. A related recent research report proposes that mass timber wood-based structural solutions can be cost-competitive for mid-rise structures and have a lighter carbon footprint than concrete or steel. A quick glance through the report reveals the use of steel beams to structurally address ductility issues affecting wind and earthquake design, and the use of concrete for foundation design. This hybrid design approach, with wood providing the primary structural and architectural material, is compelling and controversial, and it is stirring dialogue throughout the design community.

You can find many amazing large wood structures throughout the world, such as the Metropol Parasol located in Seville, Spain (shown here). There are also design awards specifically for innovation in the design of wood buildings, including Woodworks annual design awards. Some of the 2012 award winners are exceptional.

In the light-frame construction industry most of the structural wood materials are repetitive framing members that are hidden from view. Floor joists, wall framing, window and door headers, and roof trusses are rarely visible once the exterior cladding and interior finishes are applied. Yet when properly built these structures are highly resilient against wind, snow, earthquakes, and other loads.

As with any other material, wood presents its own share of challenges for structural design, including issues such as rot and insects. Fire protection can also be a concern although it is interesting to note that large wood structural members are resistant to fire because once the outer fibers burn, the charred remains form a barrier protecting the inner fibers.

I believe many designers and engineers will agree that wood is a versatile, reliable material that is easy to work with and has excellent strength and stiffness characteristics. Reading and learning about the spectacular structural innovations that architects and engineers have accomplished using wood as their primary material is enjoyable. What is your favorite wood structural project? I’d love to learn about it!

Johnny Drozdek, Keymark

Trusses are made from various materials, including the most popular: light and heavy gauge steel and wood. Trusses come in two and three-dimensions and the triangles are connected with various types of materials such as screws for steel trusses or metal plates for wood trusses. One of the most famous structures in the world, the Eiffel Tower, is a truss – a series of inter-connected triangles. Trusses are also used to construct bridges, roofs, floors, and even the Statue of Liberty.

Trivia: He designed both the Eiffel tower and a portion of the Statue of Liberty. (Cue the Jeopardy theme music). Answer: Who is Gustave Eiffel? The Eiffel tower was designed by Gustave Eiffel and the Statue of Liberty was designed by Frédéric Bartholdi, with the help of Gustave Eiffel who designed the interior structure.

Some historians have stated that trusses date back to 18th century Greece, and others argue that there are 13^th century structures in Italy that contain trusses. I have not been to Italy or Greece (yet) so I cannot verify these facts for myself. However, I have an amazing resource at Keymark that I can call upon for assistance, Bill Bolduc. Bill is our resident Structural Engineer who has a vast amount of valuable information to share about trusses and their structural stability. Recently, Bill presented Part 5 of his “Introduction to Structural Design” series, which included a review of “What is a Truss?” Bill is an internal resource that I am extremely grateful for as I learn more about trusses and structural engineering. In addition, Bill introduced me to a great external resource for learning more about trusses and structural engineering, Col. Stephen Ressler, Ph.D., P.E., U.S. Military Academy at West Point. You can review Ressler’s video series at: The Great Courses.

What internal and external resources have been most valuable to you in learning about trusses?

Christina Huerta

Last week the National Home Builders Association (NHBA) hosted its annual International Builders’ Show (IBS) in Orlando, Florida. IBS is the largest light construction show with over 47,000 building industry attendees and over 800 exhibitors. Although the home building industry is still crawling back to its former self, IBS has held steady with attendees and exhibitors over the last several years. In 2012, the attendance numbers were almost identical to 2011, but last year consumers were window-shopping and non-committal. This year, many industry experts and exhibitors noticed one major difference – People Are Buying!

So why are tradeshows consistently well attended, and in a recovering but still weak economy, how do exhibitors justify the large expense of attending tradeshows? Tradeshows are historically a traditional marketing practice dating back to the first New York World’s Fair in 1853 (photo credit: Otis Elevator Co. Historic Archives). Today, with customers at our fingertips on the web, why do consumers and exhibitors still flock to tradeshows? Is it the attraction of being able to touch and feel products at shows like IBS or the opportunity to meet face to face with customers and size up the competition? What if large companies begin to pull out of tradeshow exhibition, would tradeshows cease to exist?

Back in 1988, I attended my first tradeshow as a press correspondent – The Detroit Auto Show. This show has historically been one of the largest and most well attended shows in America for many years. Although the Auto Show has seen dramatic declines in attendance over the last several years, exhibitors and the show itself have responded to the need to reinvent themselves to attract attendees. Traditional booths with product displays, brochures and a nice movie are not good enough anymore. Companies like Toyota have found a new way to attract a different audience and to interact hands-on with consumers. Their popular, interactive vision wall allows customers to personalize their “dream car” while learning about the benefits offered by Toyota's vehicles.

Exhibit booths at home builder shows, such as IBS have come a long way from their bikini-clad displays, and exhibitors are finding fun ways to attract consumers, such as fresh baked cookies and games of chance to win prizes, but the industry as a whole has a long way to go to catch up with interactive technology. Which shows are on your marketing budget this year? Are there any must-see exhibits or did we already see the best of the light construction industry at IBS 2012?

In mid-November, I wrote a blog, "How to Become a Truss Designer." Much to my surprise, this blog took on a life of its own. With approximately 100 comments on different site postings, including 87 comments on LinkedIn’s Structural Components Group, several discussions ensued. The success of this blog prompted me to share a few highlights from the blog comments.

Initially, a great debate was stirred up within the blog comments regarding whether or not a truss designer needs hands-on construction experience or only software experience to be a great designer. The debate was split down the middle with 50% agreeing that it takes hands-on/truss yard experience and 50% agreeing that a good CAD designer can learn what they need from visiting truss job sites without actually ever working in the field.

• Mark B. said, "I've always thought that a construction hands-on background gives valuable insight to design. That understanding and visualization is vital in framing concepts and contractors always appreciate when someone knows the framing side of it as well. It's much easier to design if you know the why's and how's of framing. Just because it looks good on paper or the computer screen doesn't mean it will work in the field application.”
• Bruce S. and others commented, “Framing experience is nice but a designer can learn those things through job site visits.”

I responded to these initial comments, “…most designers seemed to have taken advantage of the online courses that are now available through SBCA…I toured a truss plant yesterday and getting to see the process in person is amazingly valuable…I learned so much in just a couple hours.”

This blog also created a platform for several experienced truss designers to share “qualities and skills” that have made them successful in their careers:

• Anna F., “…having no ego.”
• Rick B., “…the best truss designer is a team.”
• Steve C., “…getting out and talking to internal customers (truss builders and sawyers) and external customers (framers) really improved my design skills.”
• Clay W., “…the greatest asset to have is to be adaptable and open to change.”
• Steve F., “Learning to read the plans and understand what the Architect is trying to convey becomes a key element in design…”

In addition to comments about how to become a truss designer, the discussion touched on several other related topics, including the dangers of relying solely on a software program to calculate designs.

• Anna F., “…a rule I like to use-is never depend on the software to catch your mistakes/errors. I calculate most things by hand. I merely use the software as a tool-like using a calculator. It produces the "shape" or "profile" of the truss quicker than drawing by hand-but ultimately I check every part of the truss-heel height, overall height, vaults, bottom chord steps, etc. I leave nothing to chance. The slightest variance in any dimension will tell me something isn't quite right.
• Kurt C., “I personally don't trust the software I check all loads and truss profiles as well.”

To read more blog comments, join the Structural Components Group or Truss, Panel & Building Components Group on LinkedIn. Thank you to everyone that commented on the blog. I appreciated your insight and willingness to share with each other.

Christina Huerta

Do you want to leave your comfort zone, learn a new software program and produce your work with new software today? You probably just answered “No.” Asking people to change the primary software they use every day can be like asking them to enter the frozen tundra in a swimsuit, but the payoff far outweighs the frustration if we can just keep things in perspective. Here are some basic tips to keep in mind when learning new software:

-         Patience matters: As daily technology users, we tend to expect to rush through new programs and learn in rapid fire motion, however this method can leave us frustrated, confused and asking ourselves, “How did I get here?” Remember to slow down, give yourself a break and don’t expect to learn everything in one day.

-         Online training webinars: One of the most useful inventions that greatly aids in learning new software is a webinar. Webinars allow a trainer to walk you through specific functions in a step-by-step manner. In addition, most live webinars, like Keymark’s Designer’s Edge, offer attendees an open question forum and deliver a recorded copy of training sessions. Being able to “pause and replay” can be invaluable when learning a new software program.

-         Practice makes perfect: Hands-on practice is the best way to dig in and learn how to use new software. If you are reluctant to jump right in, you will always feel more frustrated down the road when your boss asks you how it is going on the new software and you haven’t opened the program since your initial training session.

The benefits from learning new software can be astronomical from reducing design time to saving your company money. Although making a change can seem frustrating at first, a new software program can become so familiar that you eventually forget how you survived without it. I remember when companies switched from Corel Office to Microsoft Office and staff kept trying to avoid the change, but looking back now, I do not know how we could function today without Word, Excel and PowerPoint.

What is your favorite new software that you thought you would never be able to learn? I am sure there are some great stories out there to share.

Christina Huerta

Google+, Facebook, LinkedIn, Twitter, just to name a few, are social media outlets used to communicate both business and personal information around the world in a single click. You would be hard pressed to find a company that is not listed on the internet, and if they are not on the web, then we must ask, how will they survive? When you want to learn something, find a company or reconnect with an old friend, you turn to the internet and its social media outlets. So, how does a company decide which social media outlets to join, follow or like? And, how do the potential “Stop Online Piracy Act” (SOPA) and “Protect Intellectual Property Act” (PIPA) bills affect companies like yours and mine?

Most companies would assume that as law-abiding citizens, we would not be affected by these new internet regulating bills that may pass into law on January 24, 2012. However, that assumption is incorrect. All companies that have a website or engage in blogging or social media are affected by SOPA and PIPA. If the government or another company identifies that your website contains copyrighted material, your website can be taken down immediately by the government, and then after it is down, you can defend and petition to have your website reinstated. In addition, if someone posts comments on your blog that infringes on copyrighted material, you are liable for their comments. Do you own the copyright for every picture, sound and comment on your website? For additional information and details on how SOPA and PIPA can affect your company, HubSpot has posted an informative summary for businesses on their blog.

Keymark is active on LinkedIn and we engage with industry colleagues via LinkedIn groups. We are currently updating our Facebook page to share happenings and our training schedule. In addition, we have a YouTube channel that offers both training videos as well recent marketing campaigns. Although we tend to see little social media interaction within the structural components and truss industry, how would you feel if there were no social media outlets for our industry? Several of the large social media outlets, including Google and Facebook, are rumored to be threatening an “Internet Blackout” to express their opposition to SOPA and PIPA.

Does your company share on social media outlets, and if not, do you think they should? If SOPA and PIPA pass into law, how do you think these bills will affect you or your company?

Christina Huerta

When was the last time you conjured up your imagination? What if you could tap into the resources of your colleagues for a day or two to imagine a solution to a project that has baffled you for the last year, month or week? What would you say if your boss asked you to share your imaginary project with the company? If you are an artist, designer or you work for GE, you might already be using your “imagination at work” all the time, but in most work places, we tap into our intellectual side, not our imaginary side in the office.

This week at Keymark, we were encouraged to take a day to do just that – IMAGINE. From finding solutions to current software issues to imagining up the next big thing for our industry, Keymark staff took advantage of the opportunity to use their child-like imagination to see projects through their mind’s eye, to visualize possibilities.

Lots of light bulbs were lit this week, several ideas will continue to flow into 2012, but the largest success at Keymark was that staff worked together to think outside the box. Leaving those ideas that we are comfortable with behind for a day and thinking up different paths to solutions pushes us out of our comfort zones and into our imaginations - allowing our minds to grow to better serve our customers.

Lots of companies have well-written mission and value statements – Do you know your company's mission and values? After this week, there is no doubt in our minds that Keymark truly believes and empowers staff to work by the company’s mission and values.

What would you do if you had a day at work to just IMAGINE THAT…?

Christina Huerta

I came across this article, Martin’s Ten Rules of Roof Design, in GreenBuildingAdvisor.com and it made me think of the many days I have spent on roofs of houses or looking at plan sets, thinking through roof geometry and framing. I grew up framing houses with my father, who is a master carpenter and a wonderful teacher. Today, I have the good fortune to still be connected to the framing industry, albeit at a bit of arm’s length through Keymark technology.

This article from Martin Holladay more or less argues to “Keep It Simple, Stupid (KISS)!” and I love that KISS mentality. In many aspects of life, the KISS mentality can save time, money and frustration.

At Keymark, we often receive requests to add enhancements to the software to support virtually any arbitrary roof geometry that can be dreamt up by the human mind. From my experience, complicated geometry leads to difficult design by the building designer and the truss designer; then complex practices to manufacture the trusses; then challenges on the job site to install and brace the trusses properly; and ultimately the home owner may still endure problems with the roof. Maybe the end consumer would have been happier with a less complex roof?

What is your experience with working through this issue of complexity versus KISS? In addition, with today's influence on energy efficiency, do you see roof designs being simplified or remaining the same?

Johnny Drozdek, P.E.

After taking last week off for the Thanksgiving holiday, this week we are featuring Blog#8 from Dave Corbin's series: Mathematics of Software for Structural Engineering. To explain the mathematics of rotating an object on the computer screen, we must resort to a little trigonometry. Suppose you want to rotate point (4,1) 40^o around the origin to a new location (x’, y’):

How does the computer calculate the new point (x’, y’)? (Rotations are always performed in a counterclockwise direction; to rotate in a clockwise direction, you simply reverse the sign of the angle.) Let’s answer the question in general for any point (x,y) and any angle q. Then we’ll plug in the actual numbers and see how well the calculated value of (x’, y’) agrees with expectations. To derive the necessary equations, we need to draw two more lines perpendicular to each axis, plus one more angle r:Both shaded areas are right triangles with hypotenuse h. [If point (x,y) is (4,1), then h = 4.1321, but its actual value will turn out to be immaterial.] From elementary trigonometry we have:

• x = h cos r 
• y = h sin r
• x’ = h cos(r + q)
• y’ = h sin(r + q)

Also from trigonometry you may recall that for any two angles r and q:

• sin(r + q) = sin r cos q + cos r sin q
• cos(r + q) = cos r cos q - sin r sin q

Combining  these equations, we can solve for x’ and y’ in terms of x and y:

• x’ = h cos(r + q) = h [(x/h) cos q - (y/h) sin q] = x cos q - y sin q
• y’ = h sin(r + q) = h [(y/h) cos q + (x/h) sin q]  = x sin q + y sin q

[Do you see why the value of h doesn’t matter? Every so often something nice happens in algebra.] These are the formulas we need to calculate (x’, y’).  If q = 40^o, then sin q = 0.64279 and cos q = 0.76604; so:

• x’ = (4)(0.76604) – (1)(0.64279) = 2.42138
• y’ = (4)(0.64279) + (1)(0.76604) = 3.33719

Referring back to the original graph, you can verify that (2.42, 3.34) is the approximate location of point (x’, y’). Of course, the computer must still convert this point into screen coordinates (using the equations from Blog #6) to identify the pixel location on the screen. It must then perform identical calculations for every other point in your model, so that the entire image appears to have been rotated 40^o around the origin.

We’ll conclude with two important observations:  (1)  So far, we have assumed that the center of rotation is always the origin. To rotate around any other point (say, the midpoint of a line segment), we need two more steps. (2)  Rotating a point does not by itself create the illusion of an object spinning on the screen. To achieve this effect, you have to display the object in small successive angular increments, like a sequence of motion picture frames. A possible choice of q is 1^o. At each increment the previously-calculated coordinate (x’, y’) becomes the new point (x,y) to be rotated, summarized in the following steps:

• x’ = x cos 1^o – y sin 1^o
• y’ = x sin 1^o + y cos 1^o
• Redraw point (x’,y’)
• x = x’
• y = y’
• Repeat from the top

Dave Corbin