Application of Finite Element Method to Design of Progressive Crush Buffer Concepts for Elevators

摘要

This paper presents a new design concept of buffer for elevators, which is based on dissipating impact energy by means of non-recoverable plastic deformation, but maintaining similar performance requirements of typical hydraulic buffers on a wide range of impacting masses and velocities. Firstly, it is presented an aluminium tube with specific geometry which provides folding behaviour under impact conditions. The design process and geometry optimisation are performed by means of explicit finite element (F.E.) crush simulations with the adequate material model for the aluminium, including strain rate stiffening of the material. The tube geometry is optimised for fulfilling a maximum average acceleration requirement within the specified ranges of cabin mass and impacting velocity, being finally validated with experimental results on full size prototypes. An alternative concept is shown as well, as combination of plastic deformation buffer with a simplified oil-based damper to satisfy critical vertical strokes requirements without modifying general geometry of buffer.