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What is Steel Structure Analysis and How to Perform it?

steel structure analysis

Steel structure analysis is the process of evaluating the behavior and performance of steel frameworks under various loads, such as gravity, wind, and seismic forces. It involves assessing whether a structure can safely withstand these forces throughout its lifecycle. This evaluation is crucial for ensuring the safety, efficiency, and reliability of buildings and other steel-based constructions.

There are two primary methods used in steel structure analysis: analytical and finite element analysis (FEA). The analytical method is suitable for simpler structures and provides quick estimates using mathematical formulations. On the other hand, FEA, commonly performed using tools like Abaqus, allows detailed analysis of complex and nonlinear problems by dividing structures into smaller, manageable elements. These methods help engineers evaluate key factors such as deflection, stress, and stability, ensuring that steel structures perform optimally under different conditions.

This blog provides a comprehensive guide to designing and analyzing steel structures. It explores fundamental concepts such as solid mechanics and structural design, delving into topics like plasticity, hardening models, and damage mechanics. The blog also offers practical insights through real-world workshops, focusing on cyclic loading, failure analysis, composite structures, and earthquake effects. By the end, readers will understand how to use simulation tools like Abaqus to create safe, efficient, and resilient steel designs.

Learn Steel Structure Analysis with Abaqus. Explore +12 practical examples featuring diverse loading scenarios, including cyclic, dynamic, vertical, and horizontal loads. Master advanced analyses such as failure simulation, damage modeling, axial capacity evaluation, and earthquake effects. From bolted connections to composite joints and reinforced beams, this package equips you with the tools and knowledge to tackle any structural challenge with precision.

steel structure analysis

1. Steel Structure Analysis

Steel structures are widely used in building construction, so knowing how they behave is an important topic in many fields. To help you understand better, we’ve shared a simple overview below. You can use it to build on what you already know and make any corrections if needed.

1.1. What is Steel Structure Analysis?

Structure analysis involves evaluating the integrity and performance of steel frameworks under applied loads, such as gravity, wind, and seismic forces. This process plays a vital role in determining if a structure will withstand its expected loads throughout its lifecycle.

By using certain methods, and tools, engineers simulate various conditions to ensure the safety and functionality of steel structures.

1.2. Why is Steel Beam Analysis Critical?

Steel structures often use beams, along with other elements like columns and plates, as a basis for a structure. Beam analysis focuses on evaluating the behavior of beams, which often bear significant portions of vertical and horizontal loads in a structure. Accurate analysis prevents failures and optimizes resource usage. By examining factors like bending moments, shear forces, and deflections, engineers make informed decisions, upgrading the overall structural performance.

Failing to properly analyze these structures will result in the following:

  • Bulking
  • Overloading
  • Yielding
  • Shear Failure

collapse of a steel frame

Figure 1: collapse of a steel frame

1.3. Understanding the Steel Structure Model

A structure model is a digital or physical representation of a framework, providing insights into its behavior under various conditions. These models serve as test simulations, offering a view of the design.

steel structure models

Figure 2: Steel structure models

2. Techniques for Steel Structure Analysis

Steel structures can be analyzed using two primary approaches, each suited for different types of problems and applications:

The classical (Analytical) approach relies on mathematical formulations to solve the problems. It is best suited for simple structures with simple geometry and loading conditions, such as beams, columns, and trusses. However, due to its limitations analytical methods are often used for preliminary design, quick estimations, and educational purposes to understand the behavior of basic structures.

The finite element (FEM) method divides a structure into smaller, simpler elements, enabling the analysis of complex and nonlinear problems that are difficult or impossible to solve analytically. This numerical approach is widely used in the industry for designing and evaluating steel frames, connections, and structures subjected to irregular loading, material nonlinearity, and large deformations. It also plays a key role in advanced scientific research and simulations, allowing detailed insights into structural performance under diverse conditions.

You can learn the FEM method in practice! Explore +12 practical examples featuring diverse loading scenarios, including cyclic, dynamic, vertical, and horizontal loads. Master advanced analyses such as failure simulation, damage modeling, axial capacity evaluation, and earthquake effects. From bolted connections to composite joints and reinforced beams.

2.1. Analyzing Elements in Steel Structures

The analysis of individual elements such as beams, columns, and joints are fundamental in understanding the structural response. Engineers rely on the principles of solid mechanics to calculate these properties with high precision, making the reliability of their projections.

In static mechanics, analyzing elements in steel structures (particularly beams) involves evaluating several factors to ensure stability, safety, and efficiency. Here are the key factors examined:

  • Moment of Inertia
  • Material Properties
  • Elastic & Plastic Behavior
  • Dynamic Loading and Fatigue
  • Deflection Limits

Additionally, engineers must account for other factors below to make structural stability.

  • Load Types
  • Buckling and Stability
  • Connections and Joints
  • Stress Concentration Points

In some situations, the temperature can make the properties change their behavior so the environment is essential to consider.

2.2. Best Practices for Steel Structure Joint Analysis

Engineers employ both analytical techniques or hand calculations and Finite Element Method (FEM) simulations to evaluate steel structural analysis, especially for joint simulations.

2.2.1. Hand Calculation

Hand calculations are used for preliminary design and verification. These involve classical mechanics principles, analytical formulations, and simplified assumptions. For joint analysis, key steps include:

Based on Newton’s laws which discuss force and moment equilibrium, summation of these forces and moments is used to determine the desired answer.

ΣF=0 / ΣM=0

Example: Consider the following beam in a structure which simplified to the following mathematical model. Because we have simplified part of our problem, we can determine its deflection.

Cantilever beam

Figure 3: Cantilever beam

For the given vertical load P the reactions are as shown (figure 4). We note that they are statically indeterminate. Using a step function to represent the contribution of P to the shear, we write:

reaction forces and moments

Figure 4: Reaction forces and moments

steel structure analysis

Integrating twice with respect to x:

steel structure analysis

Then following the boundary conditions and evaluation at the point a given deflection point to be at the middle of the beam we can determine the following as the deflection amount:

steel structure analysis

For a steel 3-meter-long beam, with the E = 200 GPa, and section inertia along the respective axis 1.14 E +6, we will expect the deflection to be 1.80E-06 meters.

Based on the other mathematical formulation that is proven in the mechanics of materials we can drive the shear force, bearing stress, bending moments, bolt group in steel structure analysis, and deflection of such frames using strain energy.

You can see how hand calculations might get frustrating! But with the right education, you can go beyond this and work with simulations and FEA to analyze more complex beams and structures. Luckily, we offer a complete tutorial video package with 300 minutes of content, featuring lots of practical examples to help you become a specialist in steel structures.

2.2.2. FEM & FEA

FEM, particularly through software like Abaqus, provides high accuracy in predicting stresses and deformation patterns.

Here is the information and steps we need to simulate steel structure using Abaqus with the same example mentioned in the analytical approach.

Modeling

The first step to making a model is to make a 3D design using Abaqus or Solidworks or any other CAD designer to have our model geometry generated. Also, we would need the properties of our model such as Young’s module, etc.

Creating part

Figure 5: Creating part

 

We have different types of loadings and analyses on different structures and components in the package below; such as composite joints in beams and steel–concrete, steel-concrete composite column analysis in different loading types, Failure analysis of beam-column connection with bolt, Reduce beam section-column with a stiffener simulation in cyclic loading. There are more than that! just click on the package below.
steel structure analysis

Meshing

Secondly, we apply a mesh to define the part of the model in CAE software (in this case Abaqus) to define it.

Meshing part in Abaqus

Figure 6: Meshing part in Abaqus

Boundary Conditions

Fixed or pinned constraints are applied to simulate the joint conditions that will be defined in this step. Also, loading conditions include point loads, distributed loads, or moment applications.

Boundary conditions in Abaqus

Figure 7: Boundary conditions in Abaqus

Solvers (Abaqus Step)

Next, we must select a proper solver (Abaqus Step for example, “Static, General” step) for our simulation; after that, we should determine the outputs we need. Then create a job then run the simulation.

Outputs

And finally, by defining the Job, we can see the desired output. For example, stress analysis, deflection of certain point, contact pressure, etc. will be calculated.

According to the figure 8 we can see the deflection is 1.81 E -6 meters with the minor error of 1%.

Steel structure Analysis | beam results

Figure 8: beam results

FEM VS Analytical results

Figure 9: FEM VS Analytical results

You can learn more advanced and practical examples in our Abaqus steel structure analysis tutorial. it contains more than 200 minutes tutorial containing many types of structures and loadings.

2.3. Abaqus FEM vs. Analytical

As you can see FEM is faster and uses software simulation that is user-friendly like Abaqus, and stands out in analyzing steel structures due to its efficiency and accuracy. This speed not only accelerates project timelines but also improves data reliability by minimizing human error.

  • Accuracy & Speed
  • Complexity
  • Validation

3. Tools and Software for Steel Structure Analysis

As we discussed above the CAD model is needed using their certain software and using Abaqus software which is primarily used for CAE we can demonstrate the response of strain and stress derived by the force input to the structures.

3.1. Key Applications of Steel Structures

Steel structures find applications across a wide range of industries, including construction, transportation, and energy. Skyscrapers, bridges, and industrial plants rely heavily on steel due to its strength-to-weight ratio, adaptability, and durability.

Steel structure

Figure 10: Steel structure

4. Designing Efficient Steel Structures

Steel structures form the backbone of modern construction, offering durability, strength, and versatility. Designing these structures efficiently requires a deep understanding of solid mechanics, advanced material modeling, and practical insights gained from simulation and analysis. This tutorial package is tailored to provide comprehensive knowledge and hands-on experience using Abaqus for the finite element analysis (FEA) of steel beams, columns, and connections under various loading conditions.

4.1. Solid Mechanics and Structural Design

Solid mechanics is fundamental to the design and analysis of steel structures. It enables engineers to predict how structures respond to forces, displacements, and environmental conditions. In this tutorial, key concepts such as plasticity, hardening models, and damage mechanics are explored in depth to optimize the performance of steel structures.

Topics Covered:

  1. Plasticity Hardening in Abaqus
    • Understanding isotropic and kinematic hardening models.
    • Application of combined hardening in cyclic loading conditions.
  2. Subroutines for Custom Simulations
    • Writing VUMAT subroutine for kinematic hardening plasticity.
    • Implementing the UHARD subroutine for isotropic hardening.
  3. Damage Modeling
    • Introduction to the Lemaitre damage model.
    • Writing and implementing Lemaitre subroutines for failure analysis.

These fundamental theories are reinforced through practical workshops that include:

  • Cyclic loading simulation in steel beam-column structures.
  • Dynamic and failure analysis of bolted connections.
  • Finite element modeling of steel-concrete composite columns.

By mastering these concepts, engineers can design structures that are not only efficient but also resilient under complex loading scenarios.

4.2. Practical Insights for Structural Steel Design

Practical knowledge is vital when transitioning from theoretical design to real-world application. This tutorial package incorporates workshops to bridge this gap by focusing on real-world challenges and providing simulation-driven solutions.

Key Workshops:

  1. Cyclic Loading and Hysteresis Analysis
    • Simulation of steel beam-columns reinforced with CFRP.
    • Generation of hysteresis diagrams for honeycomb steel beams.
  2. Flexural and Shear Failure Analysis
    • Flexural behavior simulation of CFRP-reinforced steel beams.
    • Shear failure analysis of bolted connections under dynamic loading.
  3. Dynamic and Failure Analysis
    • Bolt failure simulation in steel joints.
    • Failure analysis of double-angle connections under dynamic loading.
  4. Composite and Stiffened Structures
    • Finite element simulation of steel-concrete composite joints.
    • Damage analysis of steel columns with stiffeners under cyclic loading.
  5. Axial Capacity and Earthquake Effects
    • Simulation to determine the axial capacity of concrete-filled double-skin tube columns.
    • Earthquake effect analysis on braced frames using kinematic hardening models.

These workshops emphasize the importance of simulation tools like Abaqus in solving practical problems, optimizing designs, and validating structural performance. With real-world case studies and hands-on exercises, participants gain insights into:

  • Optimizing material usage while maintaining structural integrity.
  • Understanding failure mechanisms to improve connection designs.
  • Enhancing earthquake resilience in steel structures.

Learn Steel Structure Analysis with Abaqus. Explore +12 practical examples featuring diverse loading scenarios, including cyclic, dynamic, vertical, and horizontal loads. Master advanced analyses such as failure simulation, damage modeling, axial capacity evaluation, and earthquake effects. From bolted connections to composite joints and reinforced beams, this package equips you with the tools and knowledge to tackle any structural challenge with precision.
steel structure analysis

steel structure analysis
steel structure analysis
steel structure analysis
steel structure analysis

5. Conclusion

This article discussed steel structure analysis, focusing on how steel frameworks behave under various forces like gravity, wind, and seismic loads. Understanding these behaviors is crucial for ensuring the safety, efficiency, and durability of steel structures in modern construction.

Steel structure analysis is important as it helps engineers design reliable and optimized structures while preventing issues such as buckling, overloading, and failure. The article covered key methods, including analytical techniques for simple structures and finite element analysis (FEA) for complex cases, highlighting the advantages of tools like Abaqus for accurate simulations.

The article was structured around key topics. Steel Structure Analysis introduced fundamental concepts like load behavior, material properties, and modeling approaches. Techniques for Steel Structure Analysis explored analytical methods for initial calculations and FEA for advanced simulations. Designing Efficient Steel Structures combined theoretical knowledge with practical workshops, such as cyclic loading, failure analysis, and composite structure simulations, offering insights into real-world applications.

In conclusion, this article provided an in-depth understanding of steel structure analysis and its methods. By exploring key principles, tools, and practical applications, readers can better analyze, design, and optimize steel structures to ensure safety and performance in diverse conditions.

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