Design of Experimental Test Bench for Determining the Stresses and Strains State of Guitar Neck

Abstract

Bending causes of neck guitar, with negative economic effects are: technology - deviations from flatness, straightness, produced during processes due to faulty adjustment of machine tools, structure / material – the wood used in guitar structure leads to deformations that exceed the terms of rigidity due to anisotropy, mechanical - occurrence rheological phenomena (wood relaxation after being subjected to stresses during machining), physical - wood moisture, humidity and ambient temperature. Bending of guitar neck occurs either after completion of manufacturing processes when the guitar is not used (case I), or after a storage period without it being stressed (case II) and after a period of use (case III). The paper presents the concept of experimental stand and a set of procedures for measuring deformations of guitar neck obtained during the bending stress in three points (Figure 1). The criteria in the design of test bench were: providing mechanical boundary conditions to simulate real conditions; ensuring mobility measuring apparatus and data recording so that it can be investigated all the structural elements of the guitar; ensure stability of the tabs and the whole stand in order to avoid measurement errors; ensure handling and maintenance of subassemblies by using ergonomic dimensions, optimum materials and interchangeable parts.