A truss is a crucial structural structure in structural engineering, consisting of a collection of straight members connected at their ends. It is commonly used for lightweight construction over long spans and is composed of long struts or bars (slender members) joined at their ends. Trusses can be categorized as simple, compound, or complex, with the simplest truss consisting of three axial members arranged in a triangulated system.
A truss is an engineering structure made entirely of two force members, where the members are organized so that the assemblage behaves as a whole. It is also known as an open web girder, and its finished vertical surface is exposed to the exterior of the building but not supported by a wall or other elements.
A truss is essentially a triangulated system of straight interconnected structural elements, sometimes also referred to as an open web girder. A structural gable is a truss whose finished vertical surface is exposed to the exterior of the building but not supported by a wall or other elements.
A truss represents a structural system whose elements are two-force members arranged in a planar triangular pattern, with each member either in tension or in tension. Trusses are commonly used to span large distances with a roof truss, which is a wooden frame of the roof that carries loads from the roof covering.
In summary, a truss is a rigid structure composed of two force members connected at their ends, used for lightweight construction over long spans.
📹 Understanding and Analysing Trusses
In this video we’ll take a detailed look at trusses. Trusses are structures made of up slender members, connected at joints which …
What is an exterior structure?
The text defines exterior structures as any improvement on a lot other than the main residential structure, including decks, gazebos, greenhouses, doghouses, outbuildings, fences, patio walls, privacy screens, and boundary or retaining walls. Parking structures are buildings used for motor vehicle parking. Existing structures are those installed or approved for installation when a wireless services provider or infrastructure provider informs a locality or the Department of an agreement to co-locate equipment on the structure.
These structures are currently supporting or designed to support wireless facilities, including towers, buildings, utility poles, light poles, flag poles, signs, and water towers. Advertising structures are physical structures or objects erected to display an advertisement or used to display an advertisement.
Is a roof truss structural?
A roof truss is an engineered structural framework comprising triangulated timbers that support a roof. It is a more efficient use of materials than traditional roofs, requiring up to 40% less timber. The prefabricated nature of these structures allows for significant time savings on-site during the installation process. There are numerous varieties of roof trusses, including those with eaves, ridges, and multiple ridges. Some of the more prevalent designs incorporate eaves, ridges, and additional ridges.
Is a truss a type of frame?
Trusses and frames are distinct structural systems in civil and structural engineering. Trusses are frameworks made of straight members connected at joints, designed for carrying axial loads with minimal material usage. They are commonly used in long-span structures like bridges. Frames, on the other hand, consist of beams and columns that form a rigid network, capable of resisting axial loads, moments, and lateral forces.
They are suitable for applications requiring structural complexity and the ability to withstand various loads, commonly used in building construction. Trusses can be envisioned as a beam, with top chords usually in compression and bottom chords in tension under vertical point load.
What type of structure is a truss?
A truss is a structural system comprising linear axial members arranged in triangular configurations and connected at pin joints. The aforementioned members are solely responsible for bearing either tensile or compressive loads along their respective lengths. Conversely, the pin joints are exclusively tasked with transmitting axial loads.
What is the definition of external structure?
All living organisms possess external structures, including roots, stems, leaves, and flowers. In the case of animals, these external structures are visible and include the body, arms, legs, and head.
Is roof considered structural?
Structural damage refers to any damage that negatively impacts the livability, soundness, or structural integrity of a home, including the foundation, roof, and load-bearing walls. It can lead to collapse or failure and can include failures in roof elements, walls, foundation, waterline, and electrical outlets. Homestead exemptions lower property taxes by removing part of the property’s value from taxation, and there are various types, including general residence exemptions, exemptions for seniors, people with disabilities, and some surviving spouses. Examples of structural damage include roof failures, wall failures, foundation failures, and waterlines above 18 inches or above electrical outlets in essential living spaces.
Is truss a superstructure?
A bridge’s superstructure, consisting of deck slab, girders, and truss, bears the load and transmits it to the substructures. The decking not only holds the load but also helps transmit pressure to the substructures. The substructure supports the superstructure and distributes the load to the footings and foundation, consisting of piers, abutments, and wing walls. These components facilitate the process of transmitting the load to the earth. The specific components of a bridge depend on its type and materials.
What is the classification of a truss?
Trusses are structural components that are designed to resist external loads and maintain structural stability. There are three main types of trusses based on their determinacy: determinate trusses, indeterminate trusses, and partially determinate trusses. Determinate trusses can be analyzed using statics equations alone, with a specific number of members and joints, making them easier to analyze and design.
Indeterminate trusses have more members and joints than necessary to maintain equilibrium, introducing redundant forces and rendering the truss statically indeterminate. To analyze indeterminate trusses, additional compatibility equations or methods like the method of joints, method of sections, or matrix methods like flexibility or stiffness methods are employed.
Partially determinate trusses combine features of both determinate and indeterminate trusses, with some members that can be analyzed using statics equations alone, while others require additional techniques. Partial determinacy can arise from various factors, such as hinges, members with varying cross-sectional properties, or supports with limited rotational constraints. The analysis of partially determinate trusses combines methods used for determinate and indeterminate trusses, depending on the specific characteristics of the truss structure. Trusses are widely used in architectural and engineering applications due to their numerous advantages.
What is considered an outdoor structure?
Outdoor structures are man-made structures exposed to natural forces, such as rain, snow, sunlight, and humidity. Soil structures are the arrangement of primary soil particles into compound particles separated by natural planes of weakness. Water control structures alter the hydraulic capacity, flood elevation, and flood hazard area limit of water, such as bridges, dams, embankments, fords, retaining walls, and weirs.
Existing structures are installed or approved for installation when a wireless services provider or infrastructure provider informs a locality or the Department of an agreement with the owner to co-locate equipment on the structure. These structures include towers, buildings, utility poles, light poles, flag poles, signs, and water towers.
Are rafters considered structural?
A rafter is a series of sloped structural pieces, typically wooden beams, that extend from the hip or ridge to the eave, wall plate, or downslope perimeter. They support the roof deck, shingles, and other roof components. Rafters, also known as stick framing, are traditionally used to frame a roof and are cut and built by a professional carpenter on the job site. Major components include the common rafter, plumb cut, ridge board, collar tie, birdsmouth cut, tail cut, ceiling joist, double top plates, and wall stud.
Is trusses a type of floor?
Floor trusses are versatile, rapid, and straightforward to install systems that facilitate the creation of larger open spaces beneath columns and partitions. They are manufactured in controlled environments, which mitigates the risk of lumber warping, shrinking, and twisting.
📹 How Trusses Work! (Structures 5-1)
We can combine tension and compression elements to form trusses that span further than the pieces from which they’re made.
What I learnt after a whole career in structural engineering is that most of the time no one really cares about getting even an efficient structure (unless it is the primary structure of something huge), let alone a theoretical optimum. The exception is design-and-build contractors where their profit margin depends on minimising materials, but of course they won’t do that at the expense of complication, which costs “more than materials”.
Hey: I have been perusal your article series on structures, and I would like to commend you on both the quality and content of these articles…really well done. In terms of trusses, which truss design do you favor for over all strength for uniform compression loads? Again, thank you for taking the time and effort to make the structure articles.
Thank you so much for taking the time to make this article. I had a basic understanding of the loads involved in a truss, but some times had a hard time determining how the load was transferred through the structure. And it turns out because I was looking at it backwards. I would look at a bridge and try to figure out the load distribution by the weight of a truck sitting on it, not as the support structure resisting that load. I’m not sure if I explained that well, but your explanations helped a lot. What finally made it click, where I had that lightbulb eureka moment, was your graphics of the hands supporting the structure. I am very grateful for that, and again I appreciate you making these articles for everybody
Paul, I have a small block of land with site P classification, it is near a river in a small town in NSW, AUSTRALIA, population about 500 people on a lucky day. I need to find the cheapest possible way to construct a building, (shop and residence). I have been thinking that perhaps a bridge design would do the trick. I have recently completed my builders course and this project is going to be my first building construction and I am interested in doing it right, so it will stand for generations after I depart the planet. Would you mind giving me asking you for a good idea on how to use trusses to span between concrete capping supported by concrete columns which themselves are resting on screw piles. The trusses would operate as beams supporting the suspended floor. The local authority, because the land is on flood zone, requires the floor to be raised half a meter (500 mm) above ground level, and the floor can be a concrete slab or timber floor. Thank you, Franklin.
Hello Paul, I’ve been trying to find the right definition or rather the exact difference between a beam and a girder, I am a marine engineer so I deal with beams and girders on a daily basis, but I find them structurally very similar so it would be great if you could help me break down their fundamentals….. Thanks for the articles… keep them coming!
Liked and subscribed. I am an engineer and having come across your website by chance I found it to be be beautiful in the simplicity with which you explain things that in our days professors bored us to death with explanations of vectors and forces that in the end left us as ignorant as we were before. Thank you Paul and please continue the illuminating work. Hopefully some young blood will stick with your presentations and learn much from them, especially in the area of being opened to the enthusiasm of learning beautiful concepts.
I’m competing in a high school bridge building competition in which the bridges will be tested from a load at a specific point. The idea of optimizing the trusses is interesting to me, but how does one go about doing that for a given structure? Is it simply shortening compression members and lengthening tension members, or is there more to it?
This is a great article, do you think you could do a article on construction cranes and all the tension and compression they face? Im sure there is such a fine balance of all the techniques you have shown us thus far. I’ve look for years for someone to give a good explanation on the engineering behind cranes and no one has been able to do a good job. Maybe you can be the first 🙂
Question for you; when I see roof trusses that are exposed as in a large warehouse type building why is it that the trusses don’t always span the entire width of the roof? The last triangle just seems to float out there, wouldn’t it make more sense to have the final triangle anchor into the bearing wall? Or is it really not necessary? Thank you, you are great teacher.
I am a land surveyor currently doing my stage. I very much hope to work on a large world-class bridge at some point in my career. I have long loved bridges and considered them the greatest expression of Human engineering – because they link People together, they span gaps, they encourage exchange and cultural fluidity. The Ancient Roman Princeps was also the “Pontifex Maximus”, the “Great Bridge-Builder”. Spanning gaps is a Human fixation, it seems. There’s so much glory in a great elegant bridge.
Hello, I ask my student to draw a symetric vertical line in the middle of the truss and prolongate the bars to that lines.The bars who cross it in the top are compressed and those crossing it on the botom are in tension respect to the flexion rule.What do you think how can I improve the technic for middle school kids.Thanks
Sir i have an ultimate question. On 6:36 you show very good tension variation braces. But what type of braces we need if we want place kettlebell ( load) not only in the center but on top of every vertical compressed stands and it will be 3d truss and the edges of the 3D truss (beam) will be rigidly fixed too??…What the best solution for such complicated situation
0:05 “When paper is flat it doesn’t do well in compression.” Why? Is the reason why this: When the compressive force is applied, there is lots of visual deformation of the paper from the original flat form. I need to understand what is meant by “stiffness”. It sounds so obvious, but I don’t think I understand. “We want to make something stiffer, so that it can take compression better”. How do I make something “stiffer”?
I once made a small truss bridge for my daughter’s cat. It was made of 1/4″ x 3/4″ pieces of white pine . Finished size was about 8 feet long and 6″ x 6″ square.. It was held together with hot melt glue. Imagine my surprise when we tested it’s actual strength. It would hold two 90lb. bags of concrete!
I wish I could of went to college and participated in programs like this. I had the absolute worst k-12 educational experience and the day I took the California high school proficiency exam was one of the happiest days of my life because I was done with school. I was bored out of my mind and my focus was on the clock counting down the time until I could go home. Who knows what I could of accomplished if I had the proper school environment. Unfortunately I have an eidetic memory so I can vividly remember every single day of school. I often wonder just how many people have similar experiences to myself. I did have one teacher who recognized my abilities and had my intelligence tested and was absolutely astonishing by my IQ score. That teacher attempted to understand how someone with my intelligence was a consistent D- student.
You have interesting numerical studies but your truss at 9:00 in the article has questionable stability- the compression members that end in the middle of the truss will likely want to buckle out of the plane. The truss at 9:49 is even worse in several ways. First the compression members that don’t continue straight from top chord to bottom chord will likely want to buckle out of the plane and all of the panels that aren’t triangular will lead to a fully pinned truss wanting to buckle in the plane. Granted some amount of fixity in the joints could control buckling in the plane.
Sr please answer if we have a truss with both end hinged to column then there will be large lateral load on column which will produce large bending moment but since we have pined end at column base plate connection the column member will not be subjected to huge moment instead the lateral force due to truss hinged effect will be transfered to concrete pedestal by non uniform bearing
As a structural bridge engineer, I often watch your clips and thoroughly enjoy them. You demonstrate great creativity and innovation in your work. Particularly impressive was the clip featuring an arch structure built on a small scale model, where you deformed its shape by applying load with your finger. Additionally, the clip discussing trusses was captivating, especially when you introduced the optimized truss, with one part functioning as an arch and carrying compression loads, while the other part acted as a cable and carried tension loads. Overall, your work is truly amazing. Thank you for creating such incredibly beautiful clips.
If i could do school all over again and this were my project to tackle. I think I’d try a design that negated the down force by utilizing a pully system that creates an upward force equal to its live dead weight. In theory if say 100,000 lbs of downward force were added to the center span via 10 truck/cars, then the pully system would create the equal upward force at center span, that force is generated by the trucks/cars themselves. IDK, im no engineer, but i think I could do it. Failure is a funny word. But it doesn’t always mean bad things. Failure could also be looked at as progress, or 1 step closer to a goal.
God bless a true educator! Paul just found your lessons when you trusses lesson came along my feed. I’m 47 big old goof who only took physics for dummies in college and nothing ever in high school. This is so very interesting and well presented. So very well done Paul, thank you. I can’t wait to get to your other content. And watch this one on trusses again.
If people only knew how much the stress members holding the tons of roof above their heads moved during heat/cold cycles, they would run from the building, never to go inside again. Any idea why historic homes did not use trusses?…….The truss concept has been understood for decades, but it’s a cheap approach at a simple solution……make the rafters and joists beefier to support the load costs more money, so this is what we have today.
So, if trusses that held up the buildings 1 and 2 of the WTC work in compression and tension with cantilever from the core columns and the outer columns, these structural components would pop out and fall in free fall acceleration onto the streets below. What was visually witnessed was a continuous destruction of each of the thousands of trusses that held up the 100 plus floors of each of the buildings disappearing while each building collapsed. What happened to these structures? They should have been littered all through the streets of lower Manhattan! Well, they were destroyed as the collapse progressed and this can only happen with sophisticated explosive forces. WTC 1, 2 and 7 were planned destructive events that initiated the advancement of the US police state around the Western World. No conspiracy here at all people! And why structural engineers like this guy do not study the WTC collapse. Thanks to the brave students and professor of the University of Alaska Fairbanks, this study was performed on WTC 7 and proved beyond any doubt that explosive force was the source of the collapse of WTC 7!!!