Structural analysis is a branch of solid mechanics which uses simplified models for solids like bars, beams and shells for engineering decision making. Its main objective is to determine the effect of loads on the physical structures and their components.
Engineers and architects must understand as much about their structures as possible. This helps them to design better models. Applying structural analysis techniques allows them to do this.
Finding its roots in software development, structural analysis has evolved. Today, architects and engineers can use structural analysis in several ways. It’s important in everything from model development through to building information modelling.
Structural analysis involves the use of graphs and diagrams to represent a system. These visual documents portray the system’s specifications in a way that others understand. In software development, you’d use it to portray the system you intend to code. However, you can apply the basic steps to your models.
Think of it in terms of the 3D models you create for clients. You need to find a logical path from the data you have to the model you want to create. Structural analysis techniques, much like building information modelling, allow you to do that. They help you to tackle complex data sets, producing an accessible structure at the end.
Structural analysis primarily focuses on the data needed to ensure a software or model performs its functions. As a result, it requires a logical approach. Engineers and architects train such skills extensively. This allows them to convert project requirements into a model or program that meets the client’s needs.
These are several benefits of using structural analysis for engineers and architects. However, you must adapt the software-oriented approach for your field. Let’s look at the steps involved in using the technique.
7 Steps To Structural Analysis
A typically structural analysis involves seven steps. Here, we’ve adapted the steps for use when designing a structure. If you follow these steps, you’ll reap the benefits of structural analysis.
Step #1 – Study the Existing Solution
In the case of architects and engineers, this step often involves studying an existing building. You may have to design a replacement for an existing structure. Alternatively, you may have a pre-existing model a client has refused.
In either case, the first step involves looking at what currently exists. Look for the problem points, and confer with your client. Ask them why the current solution doesn’t work for them.
Step #2 – Model the Current Solution
You may want to create a model for the existing building as part of your structural analysis. This is where you use the data collected in step 1. The model provides a visual representation of the faults you’ve spotted.
Sometimes, you can use this model to demonstrate why a client may need a new solution. They may be unaware of the problems you highlight.
As a side note, you can skip the first two steps if there’s no previous solution to work from.
Step #3 – Model a New System
This is where your design skills come into play. You build a new model that confronts the issues found in the old one.
Many use building information modelling for this purpose. You can input the current data sets to create the existing model, and share it using the cloud. Each stakeholder then applies their expertise to the model. In doing so, they collectively create a new, improved model.
This new model forms the basis of what you’ll present to your clients.
Step #4 – Model the Physical Environment
Lighting, the land, and the flow of people are all aspects of the physical environment. Architects and engineers must account for these external factors during their structural analysis.
Again, building information modelling may help. You can use the data you collect to determine how the physical environment affects your model. Look at things like lighting, as well as the surrounding structures.
Step #5 – Evaluate the Alternatives
Clients may want to see that the solution you develop is the best one possible. As a result, you must consider the alternatives.
Evaluate each individually, picking out its pros and cons. Use this information to explain why your model is the superior choice. The use of multiple models in building information modelling also helps. It allows you to identify and evaluate alternative solutions. Use the collected data in different ways to see how it affects the model you’ve developed.
Step #6 – Choose the Best Method
Step 5 may have shown you that a different approach works better than the method you came up with. Don’t ignore this.
If an alternative method offers a better solution, make the switch. Remember that you want to deliver the best possible solution to your client. This may involve scrapping previous work. However, it’s worth it to provide the best solution to the problem.
Step #7 – Create the Graphical Specs
You’ll probably have done this throughout the process. After all, the model you create is a graphic in its own right. You may also have various 2D and 3D drawings.
As a result, this final step often involves touching things up for final presentation standard. For example, you may have to consider how you’ll render the completed model. Alternatively, you may have to consider which digital design software package works best for the model. Some create their initial models in basic design software, before moving onto more complex software later on.
Defining Structural Analysis
Structural analysis is the process of calculating and determining the effects of loads and internal forces on a structure, building or object. Structural Analysis is particularly important for structural engineers to ensure they completely understand the load paths and the impacts the loads have on their engineering design. It allows engineers or designers to ensure a piece of equipment or structure is safe for use under the estimated loads it is expected to withstand. Structural Analysis can either be performed during design, testing or post-construction and will generally account for the materials used, geometry of the structure and applied loads.
Structural Analysis usually looks at individual structural elements, and the forces they undergo. A structural engineer will look at the structural analysis results for beams, slabs, cables and walls. All of these elements have forces applied to them, such as wind loads, dead loads (like self weight) and live loads (like people or vehicles). So it is important for the engineer to review how each of these elements behave under these loads. This is the core focus of structural analysis.
Types of Structures and Structural Members
There are several types of civil engineering structures, including buildings, bridges, towers, arches, and cables. Members or components that make up a structure can have different forms or shapes depending on their functional requirements. Structural members can be classified as beams, columns and tension structures, frames, and trusses. The features of these forms will be briefly discussed in this section.
Beams
Beams are structural members whose longitudinal dimensions are appreciably greater than their lateral dimensions. For example, the length of the beam, as shown in Figure 1.1, is significantly greater than its breadth and depth. The cross section of a beam can be rectangular, circular, or triangular, or it can be of what are referred to as standard sections, such as channels, tees, angles, and I-sections. Beams are always loaded in the longitudinal direction.
Columns and Tension Structures
Columns are vertical structural members that are subjected to axial compression, as shown in figure 1.2a. They are also referred to as struts or stanchions. Columns can be circular, square, or rectangular in their cross sections, and they can also be of standard sections. In some engineering applications, where a single-member strength may not be adequate to sustain a given load, built-up columns are used. A built-up column is composed of two or more standard sections, as shown in Figure 1.2b. Tension structures are similar to columns, with the exception that they are subjected to axial tension.
Frames
Frames are structures composed of vertical and horizontal members, as shown in Figure 1.3a. The vertical members are called columns, and the horizontal members are called beams. Frames are classified as sway or non-sway. A sway frame allows a lateral or sideward movement, while a non-sway frame does not allow movement in the horizontal direction. The lateral movement of the sway frames are accounted for in their analysis. Frames can also be classified as rigid or flexible. The joints of a rigid frame are fixed, whereas those of a flexible frame are moveable, as shown in Figure 1.3b.
Trusses
Trusses are structural frameworks composed of straight members connected at the joints, as shown in Figure 1.4. In the analysis of trusses, loads are applied at the joints, and members are assumed to be connected at the joints using frictionless pins.
What are the types of Structural Analysis?
There are various methods used to perform structural analysis, depending on the level of accuracy required by the engineer. We can define structural analysis as being any of the following methods:
Hand Calculations
Hand Calculations in Structural Analysis
Simple hand calculations are an extremely fast and easy way to evaluate the effects of simple forces on simple structures. An example would be calculating the bending moment forces on a horizontal beam. These back of the envelope calculations are standard practice in civil engineering, for those who do not wish to spend long hours designing the structure – but rather wish to know the rough forces a beam will undergo due to applied loads. Our structural engineering tutorials have some fantastic tutorials on how to perform some simple structural analysis using hand calculations.
Finite Element Analysis
Finite Element Analysis (FEA)
Finite Element Analysis (FEA) is a complex numerical method used to solve complicated problems which contain a number of variable inputs such as boundary conditions, applied loads and support types. It is a far more complicated, yet accurate method to run structural analysis compared to hand calculations. FEA requires that the structure is broken up into smaller parts (or elements) which can be evaluated individually for a more accurate estimate of the solution. This can be an extremely difficult and time consuming process to set up and run. It is common that an FEA model will comprise of matrices thousands of entries – making it pretty much impossible to be evaluated by human calculations. If you want to learn more about this then explore our stiffness method calculator to gain hands-on experience and a deeper understanding of how this works. FEA is an extremely powerful and accurate method of structural analysis and is the backbone of most Structural Analysis Software.
Structural Analysis Software
There are a great number of Structural Analysis Software that can perform the accurate FEA calculations without the difficulty of having to manually set up the complex process. SkyCiv Structural 3D is one such software which allows users to evaluate the effects of point loads, moments and distributed loads on a structure or design (SkyCiv S3D Documentation).
This method is hands down the optimal and most common method to evaluate a structure with high precision and low calculation time. Some drawbacks of standard software is that it can be inaccessible or expensive. However, here at SkyCiv we aim to completely remove such disadvantages by providing affordable structural analysis software on an online platform – ready to be used by structural analysis engineer from any computer at anytime!
