Tensile, Compressive and Bending Testing
Understanding how materials react with varying loads is the key to developing products that withstand daily requirements. Tensile, compressive and bending testing play a crucial role during the analysis of these reactions by making it possible to evaluate critical mechanical characteristics such as strength, ductility and elasticity.
TABLE OF CONTENTS
- Brief explanation: tensile, compressive and bending testing
- Tensile, compressive and bending testing at Quality Analysis
- Tensile, compressive and bending tests: destructive material testing
- How does tensile testing work?
- Compressive testing – material characteristics under compression
- What is bending testing?
- Applications
- Tensile, compressive and bending testing in summary
BRIEF EXPLANATION: TENSILE, COMPRESSIVE AND BENDING TESTING
Tensile, compressive and bending tests are destructive material tests and are used to determine the mechanical characteristics of workpieces. These methods are vital for the evaluation and determination of the strength, ductility and elasticity of materials and ensuring the materials meet the specific requirements in their applications.
TENSILE, COMPRESSIVE AND BENDING TESTING AT QUALITY ANALYSIS
At Quality Analysis we offer precise tensile, compressive and bending tests to determine the mechanical characteristics of materials as per internationally recognised standards. With modern test equipment, comprehensive knowledge of the relevant standards and extensive practical experience, we ensure you receive detailed insights into material performance; information that is indispensable for ensuring product quality and reliability.
TENSILE, COMPRESSIVE AND BENDING TESTS: DESTRUCTIVE MATERIAL TESTING
As part of materials science, these destructive test methods permit detailed material analysis. They are used to identify material defects and potential weak spots at an early stage and in this way to prevent material failure. In a wide range of industries – from construction, through vehicle manufacture, to medical technology – these methods are therefore used to increase product safety and reliability. They also form the basis for the selection of materials, product development and quality control.
IMPLEMENTATION OF THE TEST METHODS
These tests can be implemented efficiently using a universal test machine as per DIN 51221. These test machines provide the necessary flexibility and precision to meet the varied requirements of tensile, compressive and bending tests and to cover standardised as well as specific test scenarios. These test methods are aimed at obtaining a comprehensive understanding of the strength and deformation characteristics of materials under varying types of load.
HOW DOES TENSILE TESTING WORK?
The tensile test is a fundamental test method and the most frequently used in material testing. It provides detailed insights into the strength and deformation behaviour of materials subjected to a single-axis tensile load. This method is not limited to only classic materials such as metals, it is also used to test wires, yarns, films/foils and notched test specimens, as well as more complex assemblies.
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IMPLEMENTATION OF THE TENSILE TEST
In the tensile test, standardised samples with specified cross-sectional areas are stretched to fracture. During this process, the load is increased evenly, smoothly and slowly to determine the material behaviour in controlled conditions. The test can be quasi-static, with a continuously increasing load, with a constant steady-state load, or with a cyclic load to determine the cyclic stress-strain curve.
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MATERIAL PARAMETERS DETERMINED
The tensile test provides essential material parameters such as the tensile strength, the modulus of elasticity (E), the yield strength (lower and higher), the strain limit, the elongation at break, the uniform elongation and the necking. These values are derived from the force-deflection diagram, which shows the force acting on the test specimen and the change in the length of the measuring section. The test can also be undertaken at varying temperatures to analyse the behaviour of the material in different thermal conditions.
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CALCULATION AND DIMENSIONING OF COMPONENTS
The mechanical characteristics determined in the tensile test are of critical importance for the calculation and dimensioning of components, the characterisation of the processing properties of materials, as well as for quality control in production and material selection. With the increasing integration of contact-less, optical measuring instruments, the precision of the measurement results is further improving.
COMPRESSIVE TESTING – MATERIAL CHARACTERISTICS UNDER COMPRESSION
This test method is of fundamental importance for understanding the behaviour of materials under compressive loads, in particular brittle materials and metals. If supplemented with tribological assessments, which analyse the interaction between material surfaces under load, it is possible not only to evaluate materials for their strength and deformation, their long-term durability and reliability in tribological systems can also be optimised.
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IMPLEMENTATION OF THE COMPRESSIVE TEST
During compressive tests, material samples are subjected to varying loads to analyse their deformation and fracture behaviour under compression. There are different types of compressive tests, including the cylindrical compression test and the force test, each of these provides specific insights into the mechanical characteristics of the materials. During the cylindrical compression test, a cylindrical sample is compressed to analyse the behaviour of the material during compression. On the other hand, the force test measures the force applied to evaluate the behaviour of the material at various load levels.
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PARAMETERS DETERMINED
The primary result of a compressive test is the stress-strain diagram that provides important information about the mechanical characteristics of the material. Similar to the yield strength in the tensile test, the compressive yield point identifies the point in the compressive test at which the material starts to deform plastically. This diagram makes it possible to determine the yield curves for the material and provides information about the load carrying ability and the deformation behaviour under compression. The analysis of the stress-strain curve from the compressive test assists not only during material selection, it also plays an important role during quality control and the development of new materials with improved characteristics.
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SIGNIFICANCE OF THE RESULTS
The data obtained during the compressive test are crucial for the evaluation of the suitability of materials for applications in which the materials are subjected to high compressive loads. The determination of the compressive yield point and the yield curve is important particularly for the design and safety assessment of structures and components for machines, because this information helps to prevent material failure and to ensure structural integrity.
WHAT IS BENDING TESTING?
Bending testing provides valuable information about the behaviour of materials under bending stress. Sample mounting as well as the number of loads applied and their type vary depending on the test setup, which makes the bending test a flexible, informative test method.
IMPLEMENTATION OF THE BENDING TEST AND PARAMETERS DETERMINED
The stress-strain curve determined from the values acquired for the bending force and deflection is a central result of this test. Depending on the type of test, different test equipment is used. It is essential that the loads applied and the supports are designed so they are parallel and rounded (often in the form of rollers) to ensure an even force distribution. If the surfaces of the sample are not plane-parallel, the loads applied and at least one support must be designed so they can tilt to ensure there is only linear contact with the test specimen.
TYPES OF BENDING TEST
The methodology for the bending test varies primarily in the manner of how the load is applied to the sample, which results in different applications and advantages:
2-POINT BENDING TEST:
It is also known as the simple bending test. Here the force is applied at two points along the sample. Although this method is straightforward to undertake, it results in uneven stress distribution along the length of the sample and is often utilised for qualitative comparisons.
3-POINT BENDING TEST:
Here the sample is placed on two supports and the force is applied in the middle by a ram, which generates an even bending load. This test arrangement is ideal for determining the bending strength and is often used for plastics, ceramics and thin sheet metal.
4-POINT BENDING TEST:
The 3-point design is expanded with one additional load application point resulting in a constant bending moment zone. This design produces a more even stress distribution and permits more detailed analyses, particularly for materials that are susceptible to near-surface defects.
APPLICATIONS
AUTOMOTIVE INDUSTRY
Tensile, compressive and bending tests contribute to the development of safer vehicles with better performance. By evaluating the strength and ductility of metals, composite materials and plastics under tensile, compressive and bending loads, materials are identified that meet the high safety and performance requirements in this sector..
AEROSPACE INDUSTRY
In the aerospace sector, tensile, compressive and bending tests are essential, because they check the strength and reliability of materials and components. In this way, materials can be identified that meet the high safety and performance requirements in this sector. Furthermore, the tests detect material defects at an early stage and help to ensure safety and safeguard the service life of aircraft and spacecraft.
MATERIALS SCIENCE AND MATERIAL INSPECTION
In materials research, these test methods permit the characterisation of new materials and the optimisation of their mechanical characteristics for specific applications. The test methods are essential for the development of innovative materials with improved strength, elongation and deformation characteristics.
MEDICAL TECHNOLOGY
In medical technology, tensile, compressive and bending tests are important for the evaluation of biomaterials, implants and other medical devices. The tests make sure these materials can withstand the loads in the human body.
ELECTRONICS INDUSTRY
The three test methods play a role during the development and testing of electronic components and housings by evaluating their mechanical integrity under load. This evaluation is particularly relevant for portable electronics, which are often subjected to mechanical loads.
TENSILE, COMPRESSIVE AND BENDING TESTING IN SUMMARY
Based on tensile, compressive and bending tests, important mechanical properties of samples can be characterised straightforwardly. As such, statements can be made about critical mechanical aspects such as strength, ductility and elasticity. These load tests aid the development of products that withstand daily requirements, for instance in the automotive and aerospace industry, medical technology or the electrical engineering industry.
