Bolt Tightening Stress Explained | VDI 2230 Step-by-Step (ANSYS Doesn't Show This!)

Did you know that your bolts are already highly stressed before any external load is applied? When performing a Finite Element Analysis (FEA) in ANSYS, the stress results typically represent only the stresses caused by the applied loads. However, the stresses introduced during bolt tightening (pretension) are just as important and must be considered for a proper bolt strength assessment. In this video, you'll learn how to calculate the stresses generated during bolt tightening according to VDI 2230, the internationally recognized guideline for the design and verification of bolted joints. Using a real engineering example of a bolted plate connection with four M8 property class 8.8 bolts, I'll explain every calculation step, including: ✅ Assembly preload calculation ✅ Axial stress due to bolt pretension ✅ Thread tightening torque calculation ✅ Torsional shear stress in the bolt ✅ Von Mises equivalent stress during tightening ✅ Verification against the bolt proof strength according to VDI 2230 The calculations are performed step by step in Excel, making them easy to understand and apply to your own engineering projects. This video is ideal for: Mechanical Engineers Design Engineers FEA Engineers ANSYS Users Engineering Students Anyone interested in bolted joint design according to VDI 2230 🎯 What You'll Learn ✔ Why ANSYS does not show the complete bolt stress after tightening ✔ How bolt pretension generates axial and torsional stresses ✔ How to calculate bolt tightening stress according to VDI 2230 ✔ How to determine the equivalent (von Mises) stress during assembly ✔ How to verify that the bolt does not yield during tightening 📚 Next Video In the next part of this series, we'll continue with the same bolted plate connection and calculate the total stress acting on the bolts after applying the external 20 kN load. You'll learn how to: Calculate the load distribution according to VDI 2230 Determine how much of the external load is actually transferred to the bolts Calculate the total bolt stress Check the safety factor against yielding Verify whether four M8 class 8.8 bolts are sufficient for this connection Don't miss it! ⏱ Chapters 00:00 Why Your ANSYS Bolt Stress Is Incomplete 00:36 Introduction 01:18 Why Bolt Tightening Stress Matters 02:05 Engineering Model Overview 02:50 Required Bolt Data (VDI 2230) 04:15 Assembly Preload Calculation 06:30 Axial Stress from Bolt Pretension 08:20 Thread Tightening Torque 10:35 Torsional Shear Stress 12:40 Equivalent (von Mises) Stress 15:10 Verification Against Proof Strength 17:20 Summary 18:05 Preview of the Next Video 💬 Have a Question? Leave your questions in the comments below. I'll be happy to answer them and help with your bolted joint design or ANSYS simulation challenges. If you found this video helpful, don't forget to Like 👍, Subscribe 🔔, and Share it with other engineers. 🔎 Keywords Bolt Tightening Stress, Bolt Pretension, VDI 2230, Bolt Stress Calculation, ANSYS Bolt Analysis, Bolted Joint Design, Bolt Preload, Mechanical Engineering, Finite Element Analysis, FEA, Bolt Strength Calculation, Engineering Calculations, Bolt Torque, Assembly Stress, Von Mises Stress, M8 Bolt, Property Class 8.8, Structural Analysis, Machine Design, Engineering Tutorial