Afterloadingsystemen

Afterloadingsystemen are devices and configurations designed to apply additional loading to a test specimen after an initial baseline load has been established. They enable staged or progressive loading conditions to simulate service or post-processing effects, such as creep, fatigue, or residual-stress relaxation.

Typically built around a loading frame with servo-controlled actuators, afterload systems may use hydraulic, electric, or pneumatic actuation. They are paired with load transducers, displacement sensors, and a digital control system that regulates the magnitude, rate, and duration of the afterload. Some systems operate as standalone rigs; others integrate with existing test machines to extend their load-path. Safety features include overload protection, interlocks, and emergency stop devices.

Applications include material testing (metals, polymers, composites), biomechanics research (bone or tissue under additional loads), civil and mechanical engineering (component fatigue under service loads), and quality assurance in manufacturing where afterloads simulate real-world loading histories.

Key design considerations include compatibility with fixtures, alignment, calibration of sensors, temperature dependence, and control accuracy. Designers follow standards for testing machines and procedures, such as ISO and ASTM guidelines for tension, compression, and fatigue testing, to ensure repeatability and comparability of results.