In the Coffer Archives - Page 4 of 8 -

Statics and Testing

The first time I had to deal with a statics problem was first semester physics. It wasn’t too crazy – something like levers to introduce the concept of balance of forces and moments. Later, we would enjoy an entire semester-long course dedicated to statics. Beam analysis, trusses, multiple point loads, concentrated moments and other tricks Professor Meyer threw at us during his infamous Friday morning pop quizzes. It was a 7 am class, so quizzes were on Friday to make sure we showed up.

A few weeks back, we were developing anchor reactions for the new SJC steel-joist connectors when used in a kicker application. We wanted to publish anchor reactions for the given connector allowable loads so engineers could skip that step in the calculations.

SJC Steel-Joist Connector – Kicker Application

First step was a lot like statics class. Draw a free body diagram with loads and resolve the reactions. A simple model ignoring eccentricity gave us a load we knew was too small. Adding eccentricity and prying forces gave us a load that seemed way (way!!) too large. We used finite element models to better understand the forces in the connection.

Of course, there is no substitute for physical testing. So we also designed a test setup to capture the anchor tension forces directly. Eliminating as much friction from the setup as possible required some precision machining, several rounds of trial and error and a lot of patience from the lab technicians building everything. The mechanics of the final setup are fairly straightforward. The anchor rods attach to the blue load cells, which measure the tension forces in the rod directly.

The test results correlated very well with the original FEA models. I still marvel at the number of tests that go into creating one number for a load table. Of course, even knowing the anchor forces, we still ran a series of tests in metal deck – just to be sure.

Let us know what you think about the testing in the comments below.

Meet Our Genuine Connector Campaign Grand Prize Winners

As part of our Genuine Connector Campaign, we had the pleasure of meeting with customers who won our Genuine Simpson Strong-Tie® Connectors contest. The grand prize was an all-expense paid trip to the San Francisco Bay area, and the opportunity to tour our state-of-the-art lab facilities as well as meet our senior managers. There were six winners; four visited us last October and we’re looking forward to meeting two more next month.

Genuine Connector Contest Winners Tour — The Genuine Connector Contest winners getting a tour at our Stockton, CA facility.

We launched a contest last year inviting customers to tell us their Genuine story. I shared mine in this blog post last January. As I mentioned in my previous post, our founder Barclay Simpson, made his very first connector for a customer in 1956. Barc believed in doing whatever it took to help the customer succeed. Today, helping the customer remains our number one priority. Whether that’s being on a jobsite to help with a product installation, making office calls to conduct product training or spending endless hours on R&D and product testing. This is what we promise to do everyday, and we do it genuinely.

But we wanted to know what it means to you. So we asked the question, “Why do you choose Genuine Simpson Strong-Tie® Connectors?”

We received many thoughtful, amazing responses. Honestly, it was hard to choose just six to receive our grand prize! Here are our the winning entries:

“It would be very easy for me to say that Simpson Strong-Tie Connectors are the only brand available in my area, which is true, but given a choice I would always select Simpson Strong-Tie. There are several reasons why I will always purchase Simpson Strong-Tie. First, I am quite impressed by Simpson Strong-Tie research and development to improve existing products and produce new ones. I have been fascinated by the extensive research facilities depicted in online videos. Especially, a video of the four- or five-story structure on the shake table for earthquakes. Your level of R&D tells me Simpson Strong-Tie backs everything they sell. Secondly, the quality of the products is impressive. The products are clean, without sharp edges or burrs from manufacturing processes, consistent in size and fit. Third, I appreciate the Simpson Strong-Tie commitment to meeting and exceeding building codes and keeping me up-to-date with specific applications. Lastly, I am impressed with Simpson Strong-Tie as a company: its people, leadership in its field and commitment to the building industry. Simpson Strong-Tie does not just talk about it. Simpson Strong-Tie does it.” P. Austin, North Adams, MA

“Think about what the world would be like without Genuine Simpson Strong-Tie® Connectors. In the Midwest, where recent storms have ravaged many communities, the losses would have been exponentially worse. The design and construction industries rely on this product line to make design and construction simpler using Simpson Strong-Tie. We take it for granted, I’m glad Simpson Strong-Tie doesn’t.” P. Lum, Florissant, MO

“Whether it is coated, stainless or composite, Simpson Strong-Tie is my connection. None of our projects are simple. Our strength, ingenuity and commitment require us to use the best of everything. Using Simpson Strong-Tie products means “never having to say you’re sorry.” The range of your products offer solutions to the many challenges we face. Many thanks to Barclay and his people for creating a company I can count on. It’s just that simple. I look forward to meeting your team someday. Many thanks, and keep up the good work!” T. Gould, Ashaway, RI

“My customers are looking for quality and innovation that they can count on. For years we have experienced that quality with Simpson Strong-Tie and continue to reap the benefits of products that save time and money and perform above expectations. The ability for Simpson Strong-Tie to build and ship custom products is second to none and often just what is needed to solve unexpected issues during the framing stage of our customers’ projects. Simpson Strong-Tie seems to always be ahead of code changes and working to help our customers with compliance. There is no equal!” L. Holmes, Torrington, WY

“The reason I use Simpson Strong-Tie is that they have the BEST customer service of any vendor that I have ever used. ANYONE that you get on the phone has the answer NOW on pricing, availability and any technical questions. The shipments are ALWAYS on time and in my 15 years, I have never seen a mistake. I deal with a lot of vendors and no one holds a candle to the service that Simpson Strong-Tie provides.” M. Stroupe, West Hartford, CT

“I have four reasons why I choose Genuine Simpson Strong-Tie Connectors. You can see them here in this picture. From left to right, they are Lilah, Callie, Hollie (being held), and Seth. Their safety is worth specifying connectors I can trust.” P. Giessel, Eagle River, AK

The contest may be over, but we’re still interested in your answer to the question: “Why do you choose Genuine Simpson Strong-Tie® Connectors?”

Narrow Face Installations

Engineered wood products have been used in wood-framed construction for many decades. Early forms of engineered wood include plywood as replacement for 1x wood sheathing and glu-laminated beams that could be fabricated in larger sizes with optimized material utilization. I-joists utilizing deep plywood webs and solid sawn lumber flanges solved the challenge of longer floor spans. Oriented strand board (OSB) eventually replaced plywood in the webs, while the innovation of laminated veneer lumber (LVL) became common in the flange material.

In addition to I-joists, structural composite lumber is widely used as a replacement for solid lumber. This could be for a number of reasons such as availability of longer lengths, straighter sections and higher strengths. Structural composite lumber (SCL) may be LVL, parallel strand lumber (PSL), laminated strand lumber (LSL) or oriented strand board (OSB).

Structural composite lumber has two faces. If the cross-section is rectangular, say 3½x5¼, the narrow face will show the edges of the SCL layers. In a square section, the face that shows the SCL layers is still referred to as the narrow face. Fasteners will have lower performance when they are installed in the narrow face of SCL. While this is not an issue for beams, Simpson Strong-Tie connectors such as post bases, column caps or holdowns may have reduced allowable loads when installed on the narrow face of SCL columns.

Test setup and failure mode of HDU installed on LVL

To support the use of Simpson Strong-Tie connectors installed on SCL post material, we have run many tests over the years. The reductions are published in the technical bulletins, T-SCLCLM13 (U.S. version) and T-C-SCLCLMCAN13 (Canada version). The reduction factors range from 0.45 to 1.0, and vary based on SCL material type – LSL, PSL, or LVL – and also by connector and fastener type.

It is important to understand the magnitude of the reductions. While narrow face installations may be unavoidable, engineers will need to specify the correct lumber and hardware combination to meet the design loads.

Share additional thoughts by leaving a comment.

Genuine Connector Collection Art

In this earlier post, I shared the story of my brother-in-law indicating that he thought some of the connectors specified on a swim club project were “ugly.” The contractor and I were able to come up with some other options, but I guess I’m still upset with my brother-in-law for calling Simpson Strong-Tie® connectors ugly. I’ll have to walk into his office sometime and comment on the attractiveness of his financial audits. How pretty are those nonrecurring charges, unrealized capital gains and special purpose entities?Continue Reading

Engineering Fees

Guest blogger Shane Vilasineekul, engineering manager

[Simpson Strong-Tie note: Shane Vilasineekul is the Simpson Strong-Tie Engineering Manager for the Northeast U.S. and one of our guest bloggers for the Structural Engineering Blog. For more on Shane, see his bio here.]

Are you finding it difficult to keep your fees competitive?

“Codes are becoming more complex.”

“Builders are demanding lower construction costs.”

“If I don’t allow this they will find an engineer who will.”

“Competition is stiffer.”

“New proprietary systems take too long to evaluate.”

“We have less time to do our job”

“Architects don’t give us enough to work with.”

“Other engineers are not doing it right.”

Working at Simpson Strong-Tie for 15 years, I have had the opportunity to speak with thousands of engineers and these are recurring themes. Some of these issues are way above my pay grade, but there may be something each of us can do to help keep our profession healthy.

A few years ago we had Susan Dowty from the California offices of S.K. Gosh speak at our SEA of Ohio conference. After her presentation, she stuck around to hear Steven Regoli from the Ohio Board of Building Standards. The gist of his presentation was that Ohio building officials don’t have the authority to reject sealed plans or even require calculations to be submitted unless there is clear evidence of a code violation. Midway through, a very lively discussion broke out between Susan and Steven about the responsibilities of plans examiners as they relate to structural design. On one side you have plans examiners who are licensed engineers and perform something akin to a peer review, and on the other side you have plans examiners with little engineering background that rely on the licensed engineer to ensure structural provisions are met. With some exceptions, the first view is held by many western states and the latter by many states in the South, Midwest and East Coast.

So how does this affect engineering fees? Well, when all it takes to collect a fee is a sealed set of structural plans, the temptation is there to cut corners in the design process and, in an increasingly competitive market, provide clients with a building that costs less to construct than one properly designed. I take pride in working in a profession that holds ethics in such high regard, but it only takes a few to give in and disrupt the market in a particular region. It seems like these “few” are gaining in numbers the last several years. Without proper checks and balances, this trend could continue.

So what can we do about it? I don’t think local government would be open to increasing the payroll for building departments to hire more engineers to review plans (building departments in Ohio saw some of the first and most severe cuts during the recent recession), but maybe we can help raise the bar for structural plan review. Steven Schaefer, the founder of Schaefer structural engineers in Cincinnati, decided years ago to take it upon himself to educate Ohio building departments on the fundamentals of structural engineering. He regularly presents at their meetings and has even created a guide to help plan reviewers look for proper load paths and lateral force-resisting systems. Next week he will be presenting four courses at their state conference and will be honored with an award for all his efforts over the years. We may not all be able to have the same impact, but most of us could spare a few hours each year to work with our local engineering association to reach out to building departments and offer training and support.

Leave a comment if you have some ideas on how to maintain our high standards, or better yet, share some successes you have seen in your area.

Social Media Tips for Structural Engineers

In January, our engineer Shane Vilasineekul wrote about his top ten mobile apps. Today we’re talking social media and how it can help you be better at your job. Now I know that the common notion of social media is that it is more of a place to goof off from work, but stay with me here. Think of social media as a place where people can meet. There is a big difference between bars versus a conference for professionals. While they are both places where people can meet in one spot, they perform different functions. Social media is the same way. It can be used for non-professional networking, but it can also be a helpful place where structural engineers can learn about new products, industry news and trends.

Here are ways that structural engineers can use social media:

Use Twitter for Industry Events and Trends: Twitter’s strongest point is its brevity. With a 140-character limit, tweets can really get to the point. Another reason that Twitter is useful is that it is often the social media platform where you see things unfold in real time. For example, you can search industry specific events and see tweets in live time and learn about the demonstrations and seminars your colleagues think are useful, the ones to skip, etc.

LinkedIn Is An Industry News Resource: LinkedIn is not just a place to show off your resume any more. LinkedIn is becoming a hub for industry news. Do you want to know what is going on with other structural engineers? You can join industry specific groups to share tips and ideas. It’s also good practice to follow companies and clients that you work with so you know when they launch a new product, promote a new project or even share their own social media content.

Subscribe to Blogs: Following structural engineering blogs like this one ensures that you never miss a beat about what other industry folks are saying. Subscribing to a blog post means that you can read all the content an industry blog has to offer all from the comfort of your inbox. Blogs also can cover day-of/breaking news that you can’t get from trade publications.

Facebook For Recommendations: While you may look at Facebook as a more family and friends zone, there is something to be said for interacting with fellow structural engineers on this platform. If you are friends with former classmates, you will find a bevy of articles that are helpful for you from an industry standpoint. You can also ask industry specific questions to your friends or ask for recommendations from people you know and trust. Following company pages opens up opportunities to give ideas for new products, learn new product uses, or even find out about new promotions and offers.

YouTube For Educational Videos: An educational video can be a lot more effective and useful than reading a paper. Seeing how a company does product testing may even take the guesswork from your own job. At Simpson Strong-Tie, we make videos for our YouTube channel so you can see our products in action whether it’s a test or even a DIY project.

I hope this blog post takes the guesswork out of social media for you. While these are some starter suggestions, the sky is the limit. What do you use social media for? Do you see professional benefits? Let us know in the comments section.

Educated in a FLASH, Part 2

This week’s blog was written by Branch Engineer Randy Shackelford, P.E., who has been an engineer for the Simpson Strong-Tie Southeast Region since 1994. He is an active member of several influential committees, including the AISI Committee on Framing Standards, the American Wood Council Wood Design Standards Committee, and the Federal Alliance for Safe Homes Technical Advisory Committee. He is vice-president and member of the Board of Directors of the National Storm Shelter Association. Randy has been a guest speaker at numerous outside seminars and workshops as a connector and high wind expert. Here is Randy’s post:

In my last blog post, I gave an overview of FLASH, the Federal Alliance for Safe Homes, and how Simpson Strong-Tie partners with them. Last November, FLASH held their Annual Conference. The theme of this past meeting was “15 Years of Stronger Homes and Safer Families,” and it was one of their best conferences yet.Continue Reading

Ten Apps for Engineers

Guest blogger Shane Vilasineekul, engineering manager

When Simpson Strong-Tie began supporting the use of iPads by employees, it was about the same time my Blackberry contract was expiring, so I decided to go all-in with Apple® and get an iPhone® 4s and an iPad®. Since mobile devices will not replace the heavy lifting required from most engineers’ computers, I wanted to find some apps that complemented my PC use and made me more efficient when I was away from my desk. After reading reviews and trying out a few, I eventually came up with a list of apps that I recommend. None were developed for engineers, but they are the ones I use most often. Let me know what you think of these or any of your favorites that I missed.

1. File Sharing Apps: My initial search was for a way to share files between my Apple devices and my PC. Since there is limited space in the free cloud services, I use two: Dropbox (free) for work files and Google Drive (free) for home files. Install the apps on your mobile devices and the software on your computers, create and log into your account, and you are ready to access/modify/share any of these files on any device. Both of these apps are seamlessly integrated into many other apps.

2. Organization: I am not the most organized person, so I wanted an app that would help me keep track of my many notes. After trying a few different ones, I settled on Notability ($3). I can take handwritten or typed notes, insert a picture of things like a jobsite photo or a paper handout, draw a sketch, or even insert an audio recording. Best of all, I can organize the notes in folders within the app and also back them up as PDF files to Dropbox.

3. Presentations: I regularly give PowerPoint presentations, so I started using an app called SlideShark (free) and got hooked. It is simple and remains true to the look of the original PowerPoint program. With the current version, I can access files on my DropBox account, play embedded videos, and use my iPhone as a remote when my iPad is connected to a projector. Although I still present with my trusty laptop most of the time, SlideShark is also great for practicing a presentation on a mobile device anywhere you find yourself with a few spare minutes.

4. Calculator: I was shocked to find that my iPad didn’t have a built-in calculator app. I tried a few free ones, but never really liked them. Then MyScript Calculator (free) came out last year, which solves handwritten equations like the one shown in the icon. Now I look for reasons to use it. It won’t ever replace my TI-85, but I am not sure I want it to.

5. Reference Guides: I like the idea of having electronic versions of my codes and referenced standards all saved in my iPad. Some of the PDF files I purchased allow me to save them in iBooks (free); others shown in the screenshot are just covers. On a side note, ICC has all of their codes online, broken into sections (as opposed to a single PDF). It’s great for sending links of specific code language to people that don’t own the code.

6. Editor Apps: There are tons of PDF editing apps out there. I asked around to see what other engineers use and decided on GoodReader ($5). I have been pretty happy with it, mostly using it to mark up PDF files I am reviewing.

7. Photos: When out on a jobsite, there is no better way to capture information than with a picture. But when everything can’t fit inside the viewfinder, PhotoSynth (free) is a great tool to capture the surroundings. Immersive 360° images can be posted online, shared, or viewed within the app. Here are links to a couple of mine: Hurricane Sandy, Columbus Test Lab.

8. Photo Editing: While on the topic of photos, I use Snapseed (free) whenever I need to edit them. It is simple and intuitive, but powerful enough to get the job done.

9. Scanner Pro ($3) turns your camera into a scanner. Take a picture of a paper document, then locate the corners of the paper within the app and turn it into a PDF file that scales and stretches it to look like a scan instead of a snapshot.

10. Sketch Apps: My favorite apps for sketching a new connector idea, illustrating a concept or just doodling, are Paper (free) and SketchBook Express (free). Paper is more free-form and natural, while SketchBook has more tools and provides more precise control. They are free, so give them both a try.

*Apple, the Apple logo, iPhone and iPad are trademarks of Apple Inc., registered in the U.S. and other countries.*

What are your thoughts? Visit the blog and leave a comment!/p>

How to Safely Select Nail Substitutions for Connectors

A few days ago, I was speaking to a customer about an application using nail substitutions for a joist hanger installation. Her questions come up often, so I thought I would dedicate a blog post to some of the resources available that cover the use of different nails in connectors.

Designers and builders often wish to use different fasteners than the catalog specifies. The application could require short nails that don’t penetrate through the back of a ledger or they want to use screws or sinker nails for easier installation. The Wood Connectors Catalog provides multiple options for alternate nailing for face mount hangers and straight straps on page 27.

The load adjustments for alternate fasteners cover substitutions from a common diameter of 16d to a 10d, or a 10d to an 8d. Multiple different replacement lengths are also covered, with reduction factors ranging from 0.64 to 1.0.

It is important to remember that double shear hangers require 3” minimum joist nails. Short nails installed at an angle in double shear hangers will not have adequate penetration into the header.

Fastener - Double Shear — Fastener – Double Shear

Pneumatic nail guns used for connector installation are commonly referred to as positive placement nail guns. These tools either have a nose piece that locates connector hole, or the nail itself protrudes from the tool so that the installer can line the nail up with the hole. Most positive placement tools do not accept nails longer than 2½”, so framers using these tools will want to use 1½” or 2½” nails. To accommodate installers using pneumatic nails, we have a technical bulletin T-PNUEMATIC. This bulletin provides adjustment factors for many of our most common embedded holdowns, post caps and bases, hangers and twist straps.

The question of nail size also comes up when attaching hangers to rim board, which can range from 1” to 1¾”. The adjustment factors in C-2013 don’t necessarily apply with rim board, since the material may be thinner the length of the nails used. We also have a technical bulletin for that application – T-RIMBDHGR.

Several of the reduction factors are the same as those in the catalog. Testing of hangers with 10dx1½ nails on 1” OSB or 1¼” LVL did not do as well, however. We observed that once the nails withdrew a little bit under load, they quickly lost capacity. For that reason, we recommend full length 10d or 16d nails on those materials.

Understanding that alternate fasteners are available for many connectors can help you pick the right fastener for you application. When you specify a connector, it is important to also specify the fasteners you require to achieve your design load.

What are your thoughts? Visit the blog and leave a comment!

Know Your Code

I attended a CFSEI and Steel Framing Alliance webinar last week entitled Specifying Cold-Formed Steel: Finding and Avoiding Pitfalls in Structural General Notes and Architectural Specifications. The presenter was Don Allen, P.E., from DSi Engineering, LLC, and he focused on issues specifically related to design and specification of cold-formed steel (CFS) in contract documents.