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The objective of this work is to introduce a new method to carry out design optimization of a mechanical system for vibration and shock isolation, in particular, the viscous spring isolator mounting system for a forging hammer.

The system dynamics model for an isolated foundation and solution technique for obtaining system response under impact loads is introduced. A design optimization problem is formulated to minimize the maximum impact force transmissibility under design constraints, using stiffness and damping coefficients of the isolator, mass of the foundation block and support area of soil as design variables. A dedicated simulated annealing (SA) algorithm is applied to solve the optimization problem.

Viscous spring isolator mounting system, if properly designed, can considerably reduce shock and vibration transmission and the size of the foundation. The optimization leads to a mounting system with superior impact and vibration isolation capability over conventional designs. Sensitivity study and design optimization on a typical 3‐ton forging hammer has demonstrated the advantages of the new design method.

To further improve the accuracy of the design optimization, a more detailed system dynamics model might be introduced.

The work leads to a better design method for viscous spring isolator foundation systems.

This study forms the foundation for further research on design optimization of viscous spring isolator foundation systems, and contributes to the application of SA optimization technique to engineering design.

The objective of CNC machining is to produce mechanical parts with designed quality most efficiently. To generate CNC tool paths for machining a sculptured part using a three‐axis CNC machine, surface geometry, cutter shape and size, as well as tool path interval and direction need to be considered. In this work, the relation between the direction of a tool motion and cutting efficiency is studied. A new measure of cutting efficiency in three‐axis CNC milling – the length of effective cutting edge (ECE) is introduced. The ECE length is mathematically proven to reach its maximum when the tool cuts a sculptured surface along its steepest tangent direction at the cutter contact point. The steepest tangent direction is thus proven to be the most efficient tool feed direction in three‐axis sculptured part machining. The study identifies tool feed direction as a new control parameter in CNC tool path planning, and forms the foundation for further research on three‐axis tool path generation of sculptured parts.