Dynamic Testing
An Introduction

A dynamic testing machine performs repeated loading mechanical testing. Where a tensile testing machine would apply a quasi-static load to measure the yield stress and ultimate tensile strength until the specimen reaches its break or rupture point, a dynamic testing machine usually stresses a material within its elastic region with cyclic loads until the specimen fails due to fatigue. The typical types of testing include high cycle fatigue, low cycle fatigue, fracture mechanics including pre-cracking, thermo-mechanical fatigue, and simulated tests such as athletic footwear, auto-injectors or stents. Dynamic testing machines utilize various technologies including servo hydraulic actuators, servo electric motors and linear electric motors.

Components and Parts

Fatigue tests are performed on dynamic testing machines. A dynamic testing machine consists of a test frame that is equipped with a load cell, testing software, and application-specific grips and accessories, such as extensometers. The type of material being tested will determine the type of accessories needed, and a single machine can be adapted to test any material within its force range by simply changing the fixturing.

dynamic testing system setup 

Dynamic Testing Machine
1) Load Frame
Dynamic testing machine load frames can come as either Servo-hydraulic, Servo-electric or Linear-Electric depending on their force capacity and dynamic performance.
2) Software
Test software is where operators can setup the machine, create test methods, run the test and export the results.
3) Load Cell
The load cell is a transducer that measures the force applied to the test specimen. Instron’s patented Dynacell’s also incorporate accelerometers to remove the errors in load introduced by inertia from high speed dynamic testing.
4) Grips and Fixtures
A wide range of specimen grips and fixtures are available for specimens of different materials, shapes, and sizes.
5) Strain Measurement
Some test methods require measurement of a specimen’s elongation under load. Instron supplies several contacting and non-contacting devices suitable for dynamic strain measurement and control.


Dynamic testing machines are available in a variety of different sizes, force capacities ranging from 1000 N to 5 MN, and dynamic performance from 1 Hz to 100 Hz. Most low force dynamic testing is performed on a linear electric motor machine, while higher force applications require Servohydraulic frames and actuators. Instron's ElectroPuls systems are available in capacity ranges from 1000 N to 20 kN and can perform a wide range of different test types, including tension-tension, tension-compression, compression-compression, bend fatigue, and a wide array of biomedical standards. Instron’s Servohydraulic systems are designed for higher capacity testing from 25 kN to 5 MN for testing stronger materials and larger components such as high strength steels and advanced composites.

Standards for Testing Plastics, Elastomers, and Metals

Most dynamic testing is performed on established standards published by standards organisations such as ASTM and ISO. Testing standards prescribe acceptable test parameters and results for different types of raw materials such as metals, plastics, elastomers, textiles, and composites, as well as for finished products such as medical devices, automotive parts and consumer electronics. These standards ensure that materials and products entering the supply chain display predictable mechanical properties and are not likely to fail in their expected end use. Since the cost and safety implications of product failure cannot be overstated, companies and encouraged to invest in high-quality, accurate testing equipment that is designed to help them easily determine whether or not their products meet applicable standards.


ASTM E647 / E399 / E1820

Bluehill Fracture modules support all common test standards (ASTM, ISO and BS) for crack propagation, ductile and brittle fracture, crack length measurements and specimen geometries. Users can test to predefined standards (e.g. ASTM E647, ASTM E399, ASTM E1820, ISO 12135).

ISO 14801

With an array of implant sizes and geometries, angled dental implants can be mounted into a variable angle fixture for testing to the ISO 14801 standard. The fixture needs to ensure that the mounting does not over constraint the implant nor generate large lateral forces that can damage the load cell or the testing machine. Pre-angled dental implants should be tested in ambient air using a frequency of 15 Hz.

ASTM F1717

The Instron spinal fixture is designed to meet ASTM F1717-12 requirements. In accordance with the standard, the UHMWPE blocks are attached to the spinal fixture. The design of the blocks can differ, according to the clinical application at the intended spinal location. The way that the blocks are connected to the fixture allow a degree of freedom when performing bending compression, bending tensile, and torsional testing.


Less Setup, More Testing

Stiffness Based Tuning is a revolutionary method of tuning your fatigue testing system, which improves your machine usability and helps to improve your data accuracy. The new process is simple for all users, and without pre-cycling the specimen it helps to make your data more reliable and repeatable.

Stiffness Specimens

Quicker Process
Quicker Process
Over 75% time saving by using patented tuning technique
More Accessible
More Accessible
Simple process builds user confidence and reduces reliance on experts
No Pre-Cycling
No Pre-Cycling
No specimen damage before the start of your test
Improved Accuracy
Improved Accuracy
Perfectly tuned system helps to ensure reliable data and accurate peaks