ISO 10326-3:2024

Overview

ISO 10326-3:2024 - Mechanical vibration - Laboratory method for evaluating vehicle seat vibration - Part 3 - specifies dynamic dummies for Z‑axis (vertical) motion used as replacements for human participants in laboratory vibration tests of vehicle seats. The standard applies to seats in earth‑moving machinery, agricultural wheeled tractors and industrial trucks and defines technical requirements, acceptance criteria and a validation test for dummies representing two mass groups (lightweight and heavyweight). It focuses on reproducing the biodynamic response and apparent mass at the dummy–seat interface in the vertical direction.

Key technical topics and requirements

• Mass groups and sitting mass
  • Lightweight group (body mass 52–55 kg) → dummy sitting mass: 39.0–41.3 kg
  • Heavyweight group (body mass 98–115 kg) → dummy sitting mass: 73.5–86.3 kg
• Dynamic dummy types
  • Passive dynamic dummy: unpowered, uses masses, springs, dampers.
  • Active dynamic dummy: powered, uses actuators and control systems to adapt parameters.
• Apparent mass and biodynamic response
  • Dummies must reproduce idealized Z‑axis apparent mass characteristics for the two mass groups (see Annex A).
  • Validation testing is required (Clause 7) to confirm dynamic performance.
• Measuring instrumentation and signals
  • Instrumentation per ISO 8041‑1 and ISO 10326‑1; minimum bandwidth 0.5 Hz to 20 Hz.
  • Acceleration measured with an accelerometer on a semi‑rigid mounting disc; force measured with a force transducer.
• Seat contact and mounting
  • Dummy must establish realistic contact area with seat cushion and back; friction controlled to prevent sliding.
  • Seat belt/harness may be used only to stabilise the dummy frame without constraining moving parts or altering cushion deformation.
• Durability and maintenance
  • Mechanical components (springs, dampers, bearings) can change over time; regular checks following Clause 7 are required.

Practical applications and users

ISO 10326-3 is intended for:

• Test laboratories performing vehicle seat transmissibility and SEAT factor measurements.
• Manufacturers and designers of suspension seats and operator seating for heavy machinery, tractors and industrial trucks.
• Test equipment suppliers developing passive or active dynamic dummies and validation tools.
• Regulatory bodies and conformity assessors referencing laboratory test methods for seat vibration performance.

Practical value: using compliant dynamic dummies reduces reliance on human participants, improves repeatability of vertical vibration tests, and supports product development and verification of seat isolation performance.

Limitations & research guidance

• The benefit of dynamic dummies depends on seat dynamics and excitation; improvement over inert mass is most evident for suspension seats with higher natural frequency (>2 Hz).
• Dynamic dummies may overestimate isolation performance compared with participants; factors such as leg interaction require further research (noted in the standard).

Related standards

• ISO 10326‑1:2016 (basic test requirements)
• ISO 7096, ISO 5007, EN 13490 (seat test methods referenced)
• ISO 8041‑1 (measuring instrumentation)
• ISO 5353 (recommended seating setup procedures)