This value must remain below the permissible assembly preload, which depends on the bolt’s yield strength, friction conditions, and strength class. The influence of the tightening procedure is particularly evident here, leading to potentially large differences between different methods.
The 2021 edition updated the mechanical property tables for bolts and clamped materials. This includes refined values for yield strengths, tensile strengths, and thermal expansion coefficients at elevated temperatures, reflecting modern material manufacturing tolerances.
is to determine the precise dimensions and strength classes of bolts required for a specific application. It models the joint as a system of elastic springs: the bolt acts as a tension spring , while the clamped components act as compression springs The standard is essential for: Preventing Failure Modes vdi 2230 2021
The turbine gets hot. The 2021 update provides refined data on how materials expand differently, ensuring the bolt doesn't become a "permanent victim" of the heat. Step 2: The Geometry of Trust Marcus calculates the Elastic Resilience
Φ=fPfS+fPcap phi equals the fraction with numerator f sub cap P and denominator f sub cap S plus f sub cap P end-fraction Adjusted values ( Φkcap phi sub k ) are calculated for eccentric layouts. Step 8: Calculation of Bolt Load Changes Compute the fundamental force components: Relief of clamping force: Step 9: Investigation of Embedding / Relaxation ( FZcap F sub cap Z This value must remain below the permissible assembly
Step 3: Determination of the Required Minimum Clamping Force ( FKmincap F sub cap K space m i n end-sub
Manually performing the 14 steps of VDI 2230 is a lengthy and complex process. To make the guideline accessible for everyday engineering, a sophisticated ecosystem of software tools has evolved: This includes refined values for yield strengths, tensile
While modern Finite Element Analysis (FEA) is powerful, VDI 2230 remains indispensable because it provides a standardized, repeatable mathematical framework that FEA often lacks in the specific context of bolt-clamping physics. Key Calculation Steps in the 2021 Edition
The guideline provides a rigorous, step-by-step procedure (often referred to as the R-steps) to validate a joint's design: