Research On Dynamic Response Law Of Explosion-proof Wall Of Curved Explosion Surface Under Impact Loading

Over the past years,with the continuous improvement of safety awareness and the supervision of security personnel,explosion accidents have shown a downward trend,but there will be some explosion accidents every year,so it is very important to design explosion-proof walls for personnel and buildings in special places.At present,in the more common concrete explosion-proof walls,the explosion-proof faces are more straight walls,but different faces.The protective effect of explosive surface on explosion is worth discussing.In order to study the anti-explosion effect of different face walls,this paper designs the difference between arc face walls and wavy face walls when they are subjected to blast shock wave.The numerical simulation is carried out by ls-dyna.This paper makes a detailed analysis on the reduction of wall reflection and diffraction pressure by arc-facing wall.The arc-facing wall is taken as rigid wall.The variation law of overpressure behind the wall under the action of diffraction is discussed and the difference of the ability of different radians to reduce explosive shock wave by the wall is analyzed.In the analysis of the wall with wavy blasting face,the stress-strain,displacement,overpressure and failure of several different wavy face forms under different forms of plain concrete and reinforced concrete are analyzed.The concrete results are as follows.(1)In the research of arc-shaped wall,the pressure behind the wall is much smaller than that behind the straight wall.The arc-shaped wall has a better ability to reduce the overpressure behind the wall than the straight wall.In the different arc-shaped wall,the wall with 60 degrees has a better ability to reduce the wall than the wall with other arcs in the research of 30,45,60,75,90 degrees.Post-overpressure capability.(2)In the horizontal pressure change behind the wall,the pressure behind the wall first increases and then decreases,and the peak pressure at different locations from the wall also shows the same trend.And it is not that the more close to the back of the explosion-proof wall,the greater the diffraction overpressure,the peak value of the diffraction pressure will appear at a certain distance from the wall.On the vertical pressure change,the peak value of the diffraction pressure on the horizontal part of the top of the wall gradually decreases from the bottom to the top,and the overall trend of the diffraction pressure behind the wall first increases and then decreases.On the wall reflector,the air pressure presents different peak pressure curves,which are subjected to the continuous superposition of reflection pressure,and the bottom of the wall is subjected to a higher pressure.In the wavy surface,the waveform explosion-facing surface has a higher resistance to reflection pressure.(3)In the analysis of stress and displacement of wall element with wave-type blast-facing surface of plain concrete,it has better weakening effect than ordinary straight wall in stress and strain and wall displacement.In the process of resisting blast wave,several different wave-type blast-facing surfaces have different properties.When the failure condition of wall is not taken into account,the damage of wall is smaller and the rigid wall condition is more considered.The trapezoidal wavefront wall has better effect when the overpressure caused by the diffraction of the lower shock wave affects the damage of the building behind the wall.When considering the damage of the wall,the anti-cracking ability of the wall is analyzed,and the circular arc wavefront explosion-proof wall has better effect of resisting the explosive shock wave.(4)As for the reinforced concrete wave wall model,it can be seen that under the combined action of reinforced concrete,the displacement of elements in reinforced concrete decreases obviously,and the flexural performance of the wall is improved.Compared with the complete fracture failure in plain concrete,the reinforced concrete wall model only appears crack damage under explosive impact,and the reinforcement inside the wall.It also fails to achieve yield strength,which greatly improves the overall performance of the wall.