In high-speed impact experiments, the impact speed of the ice ball has a significant impact on its impact force and crushing characteristics. As the speed increases, the force generated by the ice ball during impact increases significantly, and the crushing process also accelerates. At higher speeds, the ice balls completely break up and form clusters of microparticles. Through high-speed camera recording and numerical simulation, the mechanical response of the ice ball impact can be analyzed in detail, thereby effectively evaluating and improving the impact resistance of the material. Hail Impact Testing Machine uses air pressure to launch artificial ice balls of different diameters into the module to evaluate its impact resistance.

Effects of different speeds of ice balls on hail impact experiments

Changes in impact force: As the impact speed increases, the force generated by the ice ball during impact also increases. For example, under high-speed impact, the impact force of an ice ball with a layered structure is higher than that of an ice ball with a single shape. This is because the existence of the interlayer structure delays the crushing process of the ice ball and improves its ability to transfer momentum in the impact direction.

Crushing Characteristics: The crushing characteristics of a hockey puck change as the impact speed increases. At lower speeds, the puck may not completely break up, but at higher speeds, the puck may more easily break up completely and form clusters of microparticles. In addition, when the impact speed is greater than 100 m/s, both the upper and lower hemispheres are shattered.

Material response: The different speeds of the puck also have a significant impact on the response of the material being struck. For example, for plastic films, higher impact velocities lead to larger damage areas and faster damage processes.

High-speed photography of a layered ice ball hitting a force measuring rod at high speed

Accuracy of numerical simulation: When conducting numerical simulation of ice ball impact experiment, different impact speeds need to be taken into account to ensure the accuracy of simulation results. For example, the near-field dynamics method can accurately simulate the complete process of high strain rate damage under ice ball impact, but the maximum error of the amplitude predicted for impact load in the speed range of 20-60 m/s is 18.2%.

Experimental study and numerical calculation of mechanical behavior of ice impact

According to research, the dynamic compression and splitting strength of ice balls increase with decreasing temperature at high strain rates, and the dynamic and static splitting strength of ice at different temperatures and different strain rates are different. Through experiments and numerical simulations of ice ball impact composite materials, the mechanical response analysis under the high-speed impact load of hail can effectively avoid hail impact damage.

Recording of ice ball impact process:

The impact process was recorded by a high-speed camera, and the last frame before the ice ball touched the target plate in the video was defined as the first frame of process analysis, 0.1ms.

50.8mm Ice Ball Impact Laminate Process

The experiment shows that the ice ball starts to contact at 0.2ms, but it does not completely break instantly. It can be seen that at the moment of contact, only macro cracks appear in most parts of the ball body, but it still maintains a complete ball shape; at 0.3ms, the ice ball contacts more completely, and it can be seen that the ice ball begins to deform due to the force generated by the impact, and the front end of the ice ball begins to break; at 0.4ms, only the back half of the ice ball is intact. At this time, the contact part of the ice ball generates stress waves transmitted to the surroundings due to the impact, gradually absorbing energy and starting to rebound; in the last 1.2ms-1.4ms interval, it can be seen that the position changes at adjacent moments are more obvious (as can be seen from the light on the upper left), and at this time it is in the elastic area, and the phenomenon of rebounding and swinging back and forth repeatedly occurs until the energy is dissipated and returns to rest.

After the impact experiments at different speeds, the data of each experiment were processed, and the load-time relationship of the two sizes of ice balls at different speeds was obtained. During the impact process, the fiberboard will cause load fluctuations due to the back-and-forth oscillation.

25.4mm Ice Ball Impact Load and Velocity

It can be concluded from the hail impact test that under high-speed impact conditions, the damage mode of ice balls may be different from that in normal situations. Hail Impact Testing Machine is designed to simulate the hail impact in real environments, and verify the module's impact resistance by impacting ice balls of different diameters (artificially made ice balls are used to simulate hail) with air pressure.

Hail Impact Testing Machine

E-mail: market@millennialsolar.com

Hail impact test is designed to simulate the impact of hail in real environment. Based on the MQT17 clause of IEC61215 standard, it is developed to impact ice balls of different diameters (artificial ice balls are used to simulate hail) by air pressure, and hit the module at a constant speed to simulate the impact of hail climate on the module and verify the impact resistance of the module.

Functional features:

•High-precision infrared velocity sensor

•Configured with a variety of fixtures to meet different structure

•Can meet the needs of launching ice balls with diameters of 25, 35, 45, 55, 65, and 75 mm

Through the study of high-speed impact experiments and numerical simulations, we have deeply explored the impact mechanical behavior of ice balls at different speeds and their response to materials. The Hail Impact Testing Machine verified the impact resistance of the module under simulated real hail impact conditions and provided valuable data and analysis methods for improving material design. Future research will continue to optimize experimental conditions and numerical simulation methods to further improve the impact resistance of materials and provide more reliable guarantees for practical applications.