100KN Dynamic Static Fatigue Testing Machine Electro-hydraulic Servo Fatigue Testing System

This series computer Control Electro-hydraulic Servo Fatigue Testing Machine is mainly used to detect a variety of metals, non-metallic materials and small movable member, the static mechanical properties test. It can do tensile, compression, bending, low cycle and high cycle fatigue, crack growth, fracture mechanics test under sine, triangle, square wave, trapezoidal wave, random wave, combination waveform.

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Fatigue Tensile Test Introduction

The fatigue tensile test is a specialized mechanical evaluation method focused on assessing how materials behave under repeated tensile (stretching) stress over multiple cycles. Unlike static tensile tests, which measure a material's strength under a single, constant pull until failure, this test examines the cumulative effect of cyclic tensile loading-mimicking real-world scenarios where components are repeatedly stretched, such as springs, cables, or structural fasteners. Its primary aim is to determine a material's resistance to fatigue failure when subjected to cyclic tensile forces.

Core Principles and Test Mechanics

In a fatigue tensile test, a specimen is subjected to controlled, alternating tensile stress: it is repeatedly stretched (loaded) and then either partially or fully relaxed (unloaded) in cycles. Over time, this cyclic stress can initiate microscopic cracks, which grow until the material ultimately fails-often at stress levels much lower than its static tensile strength, a phenomenon known as fatigue failure.

The test typically follows these steps:

A standardized specimen (e.g., a dog-bone shape) is clamped into a testing machine, often a servo-hydraulic or servo-electric system for precise control.
A predefined tensile stress or strain amplitude is applied cyclically, following a specific waveform (most commonly sinusoidal, but also triangular or square).
The test continues until the specimen fractures, with the number of cycles to failure recorded as the material's tensile fatigue life under those conditions.

Key Parameters and Variables

Several critical parameters shape the test and its results:

Stress amplitude: The maximum tensile stress applied during each cycle (e.g., 200 MPa). This directly influences fatigue life-higher amplitudes generally lead to earlier failure.
Mean stress: The average stress over a cycle, which can be zero (fully reversed loading) or positive (predominantly tensile). A positive mean stress often accelerates fatigue.
Frequency: The rate of cycles per second (Hz). While lower frequencies reduce heat buildup, higher frequencies can simulate rapid loading in applications like machinery.
Environment: Tests may be conducted in air, vacuum, or corrosive atmospheres to account for environmental effects on fatigue, such as oxidation or chemical degradation.

Distinction from Other Fatigue Tests

What sets the fatigue tensile test apart is its focus on unidirectional cyclic stretching. This contrasts with:

Bending fatigue tests, which involve cyclic flexing (e.g., for shafts).
Torsional fatigue tests, which use cyclic twisting (e.g., for bolts).
Tensile fatigue is particularly relevant for materials and components where stretching is the primary mode of stress, such as bridge cables, aircraft fasteners, or medical implants.

Tensile Fatigue Test Standards

ASTM E399－09 Metallic materials Kic standard test for linear elastic plane strain fracture toughness

ASTM E1820 2001 test standard for measuring fracture toughness

Electro-hydraulic Servo Dynamic static fatigue testing system Specifications

Model	KASON- HDT105B
Force capacity	100kN
Load range	2%-100%FS
Testing machine accuracy	Static indication accuracy: ±0.5% Dynamic loading accuracy: ±1%
Actuator dynamic stroke	150mm
Displacement measuring range	0～150mm(±75mm)
Displacement measurement resolution	0.001mm
Deformation indication relative error	±0.5%
Force coaxiality	≤5%
Frequency Range	0.01-20HZ (50Hz optional)
Effective distance between columns	540mm
Maximum test space	800mm (exclude hydraulic clamps)
Main test wave forms	Sine wave, square wave, triangle wave, ramp wave, random waveform and external input waveform; can realize multiple sine wave forms with different frequency or amplitude combinations; random wave forms with user-defined parameters; user-imported custom wave forms
Test control method	Load, displacement, deformation control method
Servo pump station specifications	Flow 40L/min, 21Mpa
Machine Dimensions	About 10107202900mm
Hydraulic power unit	About 1350X800X1275mm
Machine Weight	About 1200KG
Hydraulic power unit Weight	About 900KG
Power supply	AC 380V± 10%, 50Hz

Test grip
4.1	Wedge Flat Push Hydraulic Grips	Meets material the high and low frequency fatigue test Working pressure:1- 21Mpa Open structure, easy to change the jaws	1set
4.2	Round Jaw	Round specimen range: Φ5.8-11.9mm, Φ10.9-16.5mm, Φ17-22.9mm	Each 1set
4.3	Flat Jaw	Flat specimen range: 0.00-7.6mm,7.1-14.2mm, 11.7-19.1mm	Each 1set

Test software function introduction

The multi-purpose dynamic test software includes high and low cycle fatigue test software modules;

System resource management module: It can configure and display the hardware resources of the system and control the loading of static and fatigue tests.

It can realize the conversion of different control modes (position control - force control) during the test. Real-time collection, display and storage of test data.

Application software: safe and reliable, powerful, good execution, upgradeable and expandable, and capable of automatic analysis and processing of test data.

Fatigue test (low cycle fatigue, high cycle fatigue)
Stress control,Strain Control,Constant amplitude fatigue,Amplitude fatigue,Frequency conversion fatigue
Simulate the measured waveform,Random waveforms and external input waveforms; random waveforms with user-defined parameters; custom waveforms imported by users;
Multiple sine waveforms with different frequencies or amplitude combinations;

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