Analisa Struktur 1 Menghitung Reaksi Perletakan Struktur Statis Tertentu Pertemuan - 3#mercubuana

Introduction

In this tutorial, we will explore how to calculate the reactions at supports for statically determinate structures, focusing on simple beams and composite beams. This guide is particularly relevant for students and professionals in structural engineering, as understanding these concepts is essential for analyzing structures under various loads.

Step 1: Understanding Simple Beams

• Definition: A simple beam is a structural element that is supported at its ends and can carry loads applied to it.
• Types of Loads:
  • Concentrated Load: A single point load applied at a specific location on the beam.
  • Uniformly Distributed Load: A load spread evenly across the length of the beam.

Key Points

• Be familiar with the basic terminology such as "supports," "moments," and "reactions."
• Identify the type of loads acting on the beam to determine how to calculate reactions effectively.

Step 2: Analyzing Free Body Diagrams

• Free Body Diagram (FBD): A graphical representation of a body isolated from its surroundings, showing all applied forces and reactions.

Steps to Create an FBD

1. Isolate the Beam: Draw the beam and remove all supports.
2. Identify Loads: Mark all external loads acting on the beam.
3. Indicate Support Reactions: Add arrows to represent the reactions at the supports.

Practical Advice

• Ensure accurate representation of forces in your FBD to assist in calculations.
• Use consistent units for all measurements.

Step 3: Calculating Reactions at Supports

• Equilibrium Equations: Use the following equations to find support reactions:
  • Sum of Vertical Forces: ΣFy = 0
  • Sum of Moments: ΣM = 0

Example Calculations

1. For a simple beam with a concentrated load:

   • Identify locations of reactions (A and B for supports).
   • Apply ΣFy = 0 to find the reaction forces.
   • Use ΣM around one support to solve for the other reaction.

2. For uniformly distributed loads:

   • Convert the distributed load into an equivalent concentrated load acting at the center of the beam.
   • Repeat the equilibrium calculations.

Common Pitfalls

• Neglecting to account for all forces can lead to incorrect calculations.
• Ensure that your units are consistent throughout the calculations.

Step 4: Analyzing Cantilever Beams

• Definition: A cantilever beam is fixed at one end and free at the other.

Key Considerations

• The fixed end will have both vertical and horizontal reactions, as well as a moment reaction.
• Use similar equilibrium equations as with simple beams:
  • Apply ΣFy = 0, ΣFx = 0, and ΣM = 0 to find the reactions.

Conclusion

In this tutorial, we covered the fundamental steps to analyze and calculate support reactions for simple and cantilever beams under various loads. Understanding how to create Free Body Diagrams and apply equilibrium equations is crucial for effective structural analysis. Apply these principles to more complex structures as you advance in your studies or career.

For further study, consider exploring composite beams and how they behave under different loading conditions.