"Stress and Deflection Analysis of a 2D Truss Using ANSYS Workbench"

Trusses are one of the most fundamental structural elements used in bridges, towers, and buildings. They are designed to carry loads efficiently using interconnected members that experience only axial forces—either tension or compression. To ensure the safety and stability of such structures, it is crucial to analyze their stresses, deflections, and reaction forces under applied loads.

Finite Element Analysis (FEA) is a powerful numerical method used to analyze the behavior of structures like trusses. ANSYS Workbench provides an intuitive platform to perform such analyses, allowing engineers to simulate real-world conditions and obtain accurate results.

In this blog, we will solve a 2D truss problem using ANSYS Workbench. 

The objective is to determine:

Nodal Displacements – How much each node moves under load.

Stresses in Each Element – To check whether the members are in tension or compression.

Reaction Forces – The forces developed at the supports to maintain equilibrium.

By the end of this tutorial, you will have a clear understanding of how to set up, solve, and interpret the results of a truss analysis in ANSYS Workbench. Let’s get started!

Applied Forces:

At Node 3: 10,000 N (↓ Downward)

At Node 3: 20,000 N (→ Rightward)

At Node 2: 30,000 N (→ Rightward)

Boundary Conditions (Supports):

Node 1: Fixed in both X and Y directions

Node 2: Fixed in Y direction only (can move in X direction)

The above picture shows the geometry of the truss problem which was created in Ansys Workbench . As a beginner we shall neglect the material properties like Young's modulus , poison's ratio and i have created this geometry with the given dimensions and i have assigned a circular cross section of radius 20mm and  line bodies to create these sketches.

The line body was defined as a structural element, with shared topology enabled to ensure correct connectivity between nodes.

Why Use Line Bodies in Truss Analysis?

• Trusses are designed to carry axial loads only (tension or compression).
• Line elements simplify the problem and make the FEA computationally efficient.
• The cross-section is defined separately, allowing easy modifications.

After completing the geometry , click on to mechanical module which will open up a page where the rest of the problem is solved . The first step after opening up the page is to generate mesh . Here you all come up with a common doubt why we want to generate mesh and why can't the problem solve

without generating mesh? Mesh generation is a crucial step in Finite Element Analysis (FEA) because it divides the geometry into smaller elements, allowing ANSYS to compute the solution accurately. Here’s why meshing is important for your 2D truss analysis: 

1. Discretization of the Model.

2. Accurate Force and Stress Distribution.

3. Nodal Connectivity and Deformation Calculation.

4. Efficient and Faster Computation.

After meshing assign the boundary conditions,

Once assigning all the boundary conditions the next step we have step up into the answer . Before that i will explain the boundary conditions . 

* The first image shows the force that acts on its bottom right which was 30000 N that acts along positive x direction.

* The second one represents that there is a hinged support (fixed rotation) which was assigned that there is a roller support

* The third one represents the displacement which was free in x direction and was fixed in y and z directions to ensure that it allows only motion along x axis . Both the second and third image shows that it allows moving through x axis and arrests all other degrees of freedom.

* The fourth image shows that there is a force that acts along positive x direction which is equal to 20000 N.

* The fifth image shows that there is a vertical force that acts on the truss along negative y direction which was about 10000 N.

* The last image shows the combination of all five images . In other words, these are the boundary conditions that acts on the truss.

                           

Let's solve this problem in Ansys Workbench and get the required answer.

Stress

The above image shows that is the maximum stress that was experienced by the truss on the given boundary conditions and ensure we does not assign any material property as it chosen random (structural steel).The color on the material show the maximum and minimum combined stress that was experienced and also the meaning of the color is represented on the left . One can get the stress experienced by the material on each and every point by using the probe option in the display tab .

Deformation

    

• The maximum deformation is 0.00017923 m (0.17923 mm) at Node 2, which is marked in red.
• The minimum deformation is 6.1188e-6 m (0.0061188 mm) at Node 36, which is marked in blue.
• The deformation distribution follows a gradient from minimum (blue) to maximum (red), indicating how the structure deforms under the applied loads.
• The deformation is highest at the free end (Node 2), suggesting that this region experiences the most displacement due to applied forces.
• The lowest deformation occurs at a fixed/support region (Node 36), confirming that boundary conditions are restricting movement.
• The deformation values are relatively small, indicating the structure is stable and within elastic limits.

Force Reaction

* The green arrow represents the reaction force in the horizontal direction (X-axis), the blue arrow represents the vertical reaction force (Y-axis), and the red arrow represents the reaction moment.

* The reaction force is concentrated at the support, meaning the applied loads and constraints are properly balanced.

* The structure appears to be constrained at a fixed or pinned support at the leftmost joint.

* The force directions suggest that the structure is experiencing external loads, possibly at the upper-right joint, causing internal forces that translate into reactions at the support.

* This analysis confirms that the truss is stable and properly constrained under the given loading conditions.

Conclusion:

In this blog, we explored the step-by-step process of solving a 2D truss problem using ANSYS Workbench, covering geometry creation, meshing, boundary conditions, solving, and post-processing. Through this analysis, we obtained key results such as stress distribution, deformation, and reaction forces, which are crucial for evaluating the structural integrity of trusses.

The study of 2D truss systems is fundamental in engineering applications, as it helps in optimizing materials, ensuring safety, and enhancing the performance of structures in real-world scenarios like bridges, towers, and frameworks. This analysis also serves as a foundation for more advanced simulations, such as nonlinear behavior, dynamic loading, and 3D truss structures.

If you found this blog helpful, feel free to share your thoughts, ask questions, or suggest topics for future discussions. Stay tuned for more insights into ANSYS simulations and engineering analysis!