Impact Testers

What is Impact Force?

Impact force refers to the large force applied by one object to another object in a very short time when two objects collide or contact in a short period of time. This force usually has the following characteristics:

• The action time is short. During the action process, the impact force contacts the object for a very short time, usually only a few milliseconds or even shorter.
• The magnitude of the force changes quickly. Due to the short action time, the magnitude of the impact force quickly reaches a peak in a very short time and then decreases rapidly.
• Accompanied by deformation and energy conversion, the object may deform during the impact process. At the same time, the impact force will cause energy conversion, such as kinetic energy into internal energy (heat energy), sound energy, etc.
• Directionality. The direction of the impact force is usually consistent with the direction of the object collision, and it is an instantaneous force.
• In practical applications, the measurement and control of impact force is very important, such as in the fields of automobile collision testing, athlete training, engineering structure design, etc. The management of impact force can reduce injuries, improve safety and efficiency.

What is an Impact Tester?

An impact tester is a special device used to test the fracture resistance and toughness of material components under instantaneous impact loads. It is mainly used to evaluate the impact resistance of materials when subjected to impact loads. Simulate the sudden impact (such as collision, fall, explosion, shock wave) that the material is subjected to in actual applications to evaluate its ability to absorb energy and resist brittle fracture. Impact testers are widely used in the fields of material science, quality control, product research and development, especially in the automotive, aviation, construction, and other industries. Through impact testing, we can better understand the performance of materials in actual applications, thereby guiding the selection and application of materials. There are three key parameters:

• Impact energy refers to the total energy absorbed by the material before it breaks (unit: joule J), reflecting toughness.
• Fracture morphology refers to the judgment of the brittle-tough transition characteristics of the material through fracture analysis (such as fibrous/crystalline).
• Tough-brittle transition temperature refers to the critical point at which the impact resistance of the material is degraded at low temperatures.

Types of Impact Testers?

The pendulum impact tester applies impact to the sample through the swing of the pendulum. It can be used to determine the performance of metal materials in resisting impact under dynamic load, so as to judge the quality condition of the material under dynamic load. The pendulum is released at a certain height and impacts the sample at a certain speed. The energy absorbed by the sample is calculated by measuring the change in potential energy before and after the pendulum impact, so as to evaluate the impact resistance of the material.

The drop weight impact tester is suitable for the drop weight impact test of ferritic steel (especially various pipeline steels), and the sample is impacted by the free fall of the drop weight. The drop weight falls freely from a certain height to impact the sample, and the impact resistance of the material is evaluated by measuring the impact energy of the drop weight and the damage to the sample.

The non-metal impact tester is used to accurately measure the anti-pendulum impact performance of non-metallic materials such as plastics, films, paper, composite film materials, metal foils, etc. The hemispherical punch impacts and passes through the film sample at a certain speed, and the energy consumed by the punch is measured to evaluate the film's ability to resist pendulum impact.