Tensile testing machine from 5 kN to 2,500 for determining the tensile strength of materials. A tensile testing machine is used to determine the strength and deformation behavior of materials up to the breaking point. Choosing the correct tensile testing machine depends on the material to be tested and the standards to be followed.
Today, if you want to learn about Tensile Testing Machines, our guide is for you. It covers everything you need to know about Tensile Testing Machines from definition, working principle, application, applicable standards, and more. In this guide, you’ll learn everything you need to know:
1. What is a tensile testing machine?
A tensile testing machine, also known as a universal testing machine (UTM), is an material testing system that applies tensile force (pull force) to a material to determine tensile strength and deformation behavior until failure. The typical tensile testing machine consists of a load cell, crosshead, extensometer, sample grips, electronics, and drive system.
It is controlled by testing software that defines machine and safety settings and stores test parameters specified by ASTM and ISO standards. In the course of the test, the force applied to the machine and the elongation of the specimen is recorded. In order to predict how a material will perform when it is used for its intended purpose, designers and manufacturers measure the force required to stretch or elongate a material to the point of permanent deformation or fracture.
2. Characteristics of tensile testing machine
- Consider special control and data processing of flexible measured materials to achieve high precision;
- Rich functions, friendly interface, and operation mode;
- Several parameters in the setup can be changed using the built-in control module;
- Simplified modular structure, compact and ergonomic design;
- It can work independently without a computer, and is easy to perform various types of tests;
- Level 3 data security protection.
- Works with a wide variety of jigs and fixtures.
- Built-in thermal printer to print test results (QT-ETT-V2)
3. Working principles of tensile testing machine
The ability of a material to resist fracture under tensile stress is one of the most important and widely measured properties of a material, determining its application and use in different applications. Tensile strength is the force per unit area required to break a material in this way.
The material will elastically yield before the yield point; beyond the yield point, the sample will undergo permanent deformation, and the corresponding stress is called yield strength. The ultimate elongation of a material is the percentage increase in length that occurs before breaking under tension. The shape of the curve formed depends on the mechanical properties of the sample.
First, the preconditioned sample is mounted between two grips that are moved in opposite directions during the test. Changes in force and displacement are recorded by load cells fixed to the driven fixture and embedded displacement transducers, respectively. Tensile strength, tear strength, and elongation can be obtained after testing.
4. Different types of tensile testing machines
- Zwicky Line
- Almighty line
- Tensile testing machine for high test loads above 330 kN
- High-temperature test system (temperature range from -80°C to +2,000°C)
5. What are the typical components of a tensile testing machine?
- Load Cells
Load cells convert tensile forces into measurable electrical signals. All of our load cells are seamlessly compatible with all of our machine components, ensuring high product quality.
An extensometer is a strain measurement device that measures the strain on a specimen, also known as a strain gauge. Strain measurements for tensile testing are required by almost all standards such as ASTM and ISO.
- Sample Grips
Sample Grips provide a mechanical connection between the sample and the tensile testing machine. Their function is to transmit the movement of the crosshead to the sample and the test force generated in the sample to the load cell.
- Moving Crossheads
A moving crosshead is essentially a crosshead that moves up or down in a controlled manner. In tensile testing, the crosshead speed of the testing machine is directly related to the strain rate of the specimen.
- Electronics Electronics
control the moving parts of the tensile testing machine. The speed and duty cycle of the crosshead can be controlled by the microprocessor in the servo controller (motor, feedback device, and controller).
Our testing software is an extremely user-friendly, wizard-guided, Windows-based solution that allows users to set up a test system, configure and run tests, and display results.
- Drive system
The drive system provides different levels of power and frequency for the tensile testing machine motor and indirectly controls the speed and torque of the motor.
6. Automatic tensile testing
For automated tensile testing, the testing machine is equipped with a robotic testing system that takes samples from storage boxes and inserts them into the machine’s sample grips. It is also possible to connect a 2D code reader, a cross-section measuring device, or, depending on the test, a hardness tester or a roughness measuring system. The automated tensile testing system also handles sample residues.
Robotic systems offer advantages for both large and small test series:
- Automated tensile testing has so far been primarily used by laboratories with large sample volumes. A fully automated tensile testing system can be used on night shifts and weekends with consistent high efficiency, 24/7, without an operator present.
- Even for small test series starting from about 10 specimens, automated tensile testing systems have proven worthwhile. By performing tensile testing with a simple robotic testing system, qualified laboratory personnel are freed from their day-to-day duties so that they can perform more complex tasks.
Using fully automated tensile testing eliminates operator subjective influences such as hand temperature and tilted sample clamping. This results in a high level of accuracy and repeatability, and a significant increase in the quality of test results.
7. What is a tensile test?
Tensile tests are used to determine how a material responds to an applied force (pull). Tensile testing directly measures ultimate tensile strength, maximum elongation, and area shrinkage. The following properties can also be determined from these measurements: elastic modulus (Young’s modulus), deformation (Poisson’s ratio), yield strength, and strain hardening behavior.
- Ultimate Tensile Strength – The maximum tensile stress a material can withstand before breaking
- Maximum elongation – the maximum strain a material can withstand before failure
- Area Reduction—A comparison between the original cross-sectional area of a specimen and the minimum cross-sectional area of the same specimen after complete fracture failure. It is used as an indicator showing how much a material deforms when subjected to a tensile load.
- Young’s Modulus – The stiffness of a material. That is, it indicates how easily the material bends or stretches:
- Young’s modulus = stress/strain
- Stress = force / cross-sectional area
- Strain = change in length / original length
- Poisson’s Ratio – The ratio of the change in width to the change in length in the direction of the tensile force.
- Yield Strength – The maximum tensile stress an elastic material can sustain before permanent deformation occurs.
- Strain Hardening Properties – Strain hardening, also known as work hardening, occurs when a material is stretched beyond the yield point. Strain hardening increases mechanical resistance and hardness but reduces ductility. Materials that meet ductility requirements while maintaining the highest strength can be identified by manufacturers using this information.
Data obtained during tensile testing can be plotted on a graph to generate stress/strain curves. The stress/strain curve shows a curve with a high level of strain hardening and a low level of strain hardening after the yield point.
Manufacturers in industries ranging from plastics and composites to the automotive, food and beverage, and highly regulated medical and pharmaceutical industries use tensile testing equipment to perform industry-standard testing to precisely measure the defining properties of their materials, ensure compliance with standards, and ultimately ensure the quality and safety of their products.
8. Examples of tensile testing applications include:
- Plastic Packaging – Pulling is applied to samples of plastic material to help manufacturers determine the protective properties of the plastic when subjected to pulling forces such as those that occur during shipping.
- Concrete Reinforcement – Tensile testing is performed on metal samples to determine various mechanical properties such as yield strength, ultimate tensile strength, elongation, and reduction of area to help manufacturers meet not only advertised quality and high-performance specifications but also industry standards to ensure products are safely placed on the market.
- Rubber Compounds for Tires – Testing tire rubber for elongation and tensile strength for quality control to avoid tire failures such as tread separation and blowout.
In addition, the tensile testing machine can perform traction, peeling, sealing, tearing, compression, bending, shearing, and other types of tests on plastic film, composite film, plastic tape, flexible packaging material, rubber sheet, paper, non-woven fabric, and other packaging materials. It is widely used in plastic film production, packaging, medicine, food, inspection institutions, scientific research institutes, and other related industries to study the properties of materials and finished products.
9. General Standard for tensile testing
Materials testing is governed by ASTM and ISO standards. Here are some of the most commonly used tensile testing standards:
- Metals – ASTM E8 and ASTM E21 / ISO 6892-1 and ISO 6892-2
- Plastics – ASTM D638 / ISO 527-2
- Rubber and Elastomers – ASTM D412 / ISO 37
- Fiber Reinforced Composites – ASTM D3039
10. What should be paid attention to when choosing a tensile testing machine?
The following factors should be considered when selecting a machine, in addition to quality, reliability, cost, and application:
The ability to test a wide range of materials over a wide load range, the integration and easy exchange between accessories designed for each industry standard, material type, and application, the option to operate the machine with or without a PC, and the mechanical modularity that allows the machine to be expanded and adjusted using the many available test and sample grips all contribute to the overall flexibility of the testing machine.
The safety of tensile testing machines is of paramount importance, extending from the implementation of physical safety features such as external safety doors, safety enclosures, safety interlocks, and limit switches to software system monitoring and user management. We are dedicated to designing test systems that put the operator and machine safety first.
3) Ease of use
The key is to choose a test system that is sophisticated in design and highly operable while allowing operators to easily install test fixtures, set up test configurations, implement test procedures, run tests, and interpret results.
Market developments and standard requirements are always changing. When deciding on a tensile tester, you should make sure your machine can accommodate these changes – from accessories and fixtures to electronics and software programs.
The testing software is designed to make the testing process easier for operators and ensure that test configurations are consistent and compliant. Our testing software is designed with users and laboratory workflow in mind.
#1. Standard library
Our test software includes more than 600 standard test procedures, allowing you to select the correct standards-compliant procedure for your application, simplifying test setup and configuration, ultimately saving you time and effort, and reducing the possibility of error. For tests beyond the standard or for test sequences that allow free configuration of the machine, our software offers pre-prepared master test programs.
#2. Smart Guide
Smart wizards guide users through test configuration. Automatically check the plausibility of the data.
Whether simple or custom, our software allows you to define reports with virtually unlimited possibilities as well as options for saving, exporting, and printing.
The use of automation in materials testing is increasing, especially since even the smallest disturbance can alter measured values. We offer a wide range of possibilities for material testing automation. Test systems range from efficient automation of small-batch testing using cobots in laboratories to fully automated test laboratories working around the clock.
7) After-sales support
We provide individually tailored service and support throughout the entire lifecycle of our testing machines. We offer expert calibration services, preventive maintenance and inspections, training courses, machine relocation services, qualification services, hotline, and customer support, and guarantee spare parts availability for at least 10 years after a product has been discontinued.
8) Company stability
The stability of the company is a solid foundation for the machine to perform tests.