ISO 18437-5:2011

Overview

ISO 18437-5:2011 - Mechanical vibration and shock - Characterization of the dynamic mechanical properties of visco‑elastic materials - Part 5 specifies methods to estimate the Poisson ratio (and optionally the Young modulus) of isotropic visco‑elastic or porous‑elastic materials used in vibration and acoustic applications. The standard uses comparisons between measured force–deflection (stiffness) data from disc‑shaped specimens with bonded ends and axisymmetric finite element analysis (FEM) calculations to determine Poisson ratio for use in linear FEM or other numerical vibration/acoustic models. Only small deformations (linear behavior) typical for vibration problems are considered.

Key topics and requirements

• Measurement principle: Match experimentally measured stiffness (force/deflection) of bonded disc specimens to FEM-computed dimensionless stiffness as a function of Poisson ratio.
• Two methods:
  • Single‑sample method - Poisson ratio determined when Young modulus is known from other tests (e.g., ISO 18437‑2 to ‑4).
  • Two‑sample method - Poisson ratio and elastic modulus estimated together.
• Specimen geometry: Disc-shaped samples with bonded boundary conditions; shape factor S = D / (4T) (diameter D, thickness T). A minimum shape factor of 2.0 is recommended to achieve sensitivity to Poisson ratio.
• Assumptions/limits:
  • Linear dynamic behavior (small strain amplitudes).
  • No significant fluid‑structure interaction (typically valid below ~100 Hz for open‑cell foams).
  • Interfaces approximated as surface contacts.
• Data use: Frequency- and temperature-dependent complex Young modulus and Poisson ratio for numerical vibration and acoustic predictions.

Applications and users

ISO 18437‑5 supports practical tasks where accurate elastic properties are critical:

• Design and optimization of vibration isolators and resilient mounts to reduce transmitted vibrations and radiated sound.
• Material selection for isolators, pads, seals, and acoustic treatments.
• FEM analysts and acoustic modelers who require reliable Poisson ratio inputs to predict transfer functions and system response.
• Manufacturers, test labs and R&D teams for product development, specification sheets and quality control of resilient materials.
• Condition monitoring and vibration consultants using dynamic mechanical properties to evaluate isolation performance.

Related standards

• ISO 18437‑2, ISO 18437‑3, ISO 18437‑4 (measurement methods for Young modulus and loss factor)
• Normative references: ISO 6721‑1 (dynamic mechanical properties), ISO 10846‑1 (vibro‑acoustic transfer), ISO 23529 (sample preparation)

Keywords: ISO 18437-5:2011, mechanical vibration and shock, Poisson ratio, visco-elastic materials, finite element analysis, FEM, dynamic mechanical properties, Young modulus, stiffness measurement, vibration isolators.