# Energy Balance of the Dynamic Impact Stressing of Conveyor Belts
## 2 Materials and Methods
### Methodology for Impact Testing of Belts  
The Institute for Logistics and Transport at the Technical University of Kosice possesses the equipment constructed particularly for testing resistance to puncture of conveyor belts (Figure 2).  
A procedure for testing conveyor belts for resistance to puncture is described in more detail in Paper [38].  
During testing, the following parameters are varied:  
* Conveyor belt type and a corresponding tension force;
* Hammer head;
* Hammer impact height h;
* Hammer mass m;
* Support system type.  
The mass was changed by adding calibrated steel weights (\(\phi\) 200 mm) within the mass range from 50 kg to 110 kg. The head of the hammer may be of various shapes, including spherical, pyramidal, or conical. The testing described in this paper was conducted using the pyramidal and spherical impactors (Figure 3). The tests were limited by a maximum impact height of 2.6 m (limiting height of the testing equipment tower). The impact height, measured using the L-GAGE LT3 Long-Range Time-of-Flight Laser Sensor, may be set to an arbitrary value as required for the performance of particular testing. Various potential impact heights and hammer masses enable a wide range of combinations to be created. This particular stand (Figure 4) facilitates testing of any type of conveyor belts.  
Figure 1: The composition of the tested conveyor belt: (1) top cover layer; (2) carcass—polyamide’splies; and (3) bottom cover layer.  
Figure 2: The testing equipment for testing conveyor belts for resistance to puncture.  
Tests may be carried out either with a support system (supporting idlers) or without it. Both ends of a conveyor belt are fixed into hydraulic jaws and the belt is stretched using a force corresponding to 1/10 of the nominal tensile strength in the longitudinal direction in newtons, multiplied by the specimen width in millimetres. A hammer with a required impactor attached to it, of a predetermined weight, is elevated by a pulley to a required height and then dropped in free fall onto the stretched conveyor belt.  
The resistance of conveyor belts to punctures is defined as the ability of a conveyor belt to absorb the impact energy formed at the impact of a material onto the belt, i.e., absorb the entire energy by deformation processes in a conveyor belt without any resultant damage to the belt. If the impact energy is greater than the ability to absorb the entire impact energy, the conveyor belt suffers significant damage, primarily to the top cover layer, in the form of indentations, punctures, or longitudinal and transverse scratches; moreover, a puncture causes damage to the carcass of the conveyor belt which leads to the loss of its functionality. The evaluation of a test in puncture resistance testing comprises visual inspection of the conveyor belt, followed by the identification, based on the recorded measurements, of magnitudes of the impact force and the tension force at which the puncture occurred.  
Figure 4: Testing equipment diagram: 1. hammer; 2. impactor; 3. fixed stretching jaw; 4. slidingstretching jaw; 5. conveyor belt test specimen; and 6. idler support system.  
Figure 3: Impactors used: (**a**) spherical; and (**b**) pyramidal.