The influence of tube-plate electrodes on the laser mode of a fast-transvere- flow C02 laser
The distribution of the electric field of a tube-plate transversal flow discharge C02 laser is numerically solved. It is helpful to understand the formation and improvement of the laser mode.
Cutting of slate tiles by CO2 laser
Slate is a natural stone which has the characteristic that shows a well-developed defoliation plane, allowing to easily split it in plates parallel to that plane which are particularly used as tiles for roof building. At present, the manufacturing of slate is mostly manual, being noisy, powdery, and unsafe for the worker. Thus, there is a need to introduce new processing methods in order to improve both the working conditions and the quality of the products made of slate. Following previous work that focused on the drilling and cutting of slate tiles using a Nd:YAG laser, we present in this article the results of the work carried out to explore the possibilities to cut slate plates by using a CO2 laser. A 1.5 kW CO2 laser was used to perform different experiments in which the influence of some processing parameters (average power, assist gas pressure) on the geometry and quality of the cut was studied. The results obtained show that the CO2 laser is a feasible tool for successful cutting of slate.
Experimental study on ground vibration of blasting the boulder with tandem shaped charging warhead
Hazardous effects of blasting the boulder with the new breaking-blasting equipment-tandem shaped charging warhead are mainly air shock wave, seismic wave and blast slung shot. Blast-induced ground vibration is one of the inevitable effects and may cause substantial damage to nearby structures. Started from the formation process and mechanism of ground vibration to study the seismic wave, the research attained curve of vibration velocity of monitoring points by TC-4850 and carried out differential and fast Fourier transform analysis of the curve. And the results concluded that blasting vibration with tandem shaped charging warhead mainly comes from prime charge; the attenuation law can be predicted by Sadev’s Formula. Explosion vibration frequency range is 20-150 Hz, while with the increase of distance from the blasting center, blasting vibration intensity attenuates rapidly, vibration duration increases and vibration frequency gradually reduces. Compared with general rock blasting, its attenuation rate of blasting vibration is faster with higher frequency and smaller impact on buildings, but the harm effects should not be ignored for the special application environment.