Determining the required clamping force to maintain joint integrity.
Focuses on Single Bolted Joints (SBJ). The formulas assume the load acts on an isolated, individual bolt connection.
The key changes—property class 14.9, thermal preload loss, short engagement, and digital XML—reflect how modern engineering actually operates. Download the guideline from Beuth Verlag, update your calculation spreadsheets, and retrain your junior engineers.
Gather all geometry data, material properties (yield strength, Young's modulus), and the applied external loads (forces, torques, operating temperatures). R1: Estimation of Bolt Diameter vdi 2230 2021
Calculating the stiffness of the bolt ( CScap C sub cap S ) and the compressed plates ( CPcap C sub cap P
Minor algebraic corrections were made to the formulas for determining the substitution cylinder for prismatic clamped parts.
The 2021 update introduces vital revisions that align the standard with modern engineering software, advanced manufacturing methods, and updated material science. Understanding these changes is essential for mechanical engineers, structural analysts, and quality assurance professionals. Determining the required clamping force to maintain joint
Ensure the bolt is not over-tightened during assembly or over-stressed during operation.
The final steps verify the joint's integrity against failure modes like yielding, fatigue fracture, excessive surface pressure, and sliding. Key Analytical Concepts Assembly Preload ( FMcap F sub cap M
The external load or the component geometry is asymmetrical. This introduces a bending moment into the joint, causing uneven pressure distribution across the clamped interface. This requires more complex calculation using substitution deformation cones or cylinders. 3. The 13-Step Calculation Procedure The key changes—property class 14
The calculation of elastic resiliences of the connecting elements — bolt δS and clamped parts δP — constitutes the theoretical core of the VDI 2230 calculation. An estimation of the load introduction factor n is also required, which accounts for the position where the working load is introduced into the joint. The load factor φ is then calculated as:
For joints subjected to dynamic or cyclic loading, calculate the stress amplitude acting on the bolt thread. Compare this to the permissible fatigue limit of the thread to ensure the bolt will not fail prematurely due to fatigue. Step 13: Verification of Surface Pressure ( pmaxp sub m a x end-sub
The standard has refined the calculation of endurance limits. The new guidelines offer more precise methods for determining the fatigue strength of the bolt, taking into account the stress concentration factors more rigorously. This is particularly important for dynamic loading applications, such as automotive engines or wind turbines, where joint failure is often fatigue-related.