Research On Body Protection Mechanism Under The Combined Effect Of Explosion And Penetration

Explosive shock wave and fragment penetration are two main damage elements for structural damage.In the past studies,shock wave and fragment penetration are usually studied separately,and the damage studies on the combined effects of blast wave and fragment penetration are few.In order to study the damage mechanism of the combined action of the two,the dynamic analysis finite element software LS-DYNA was used to study the body protection mechanism under the combined action of blast wave and fragments.The main research contents and conclusions are as follows:(1)Establish an air-explosive-target plate model,and verify the feasibility of simulating the combined action of explosive shock waves and fragments by means of fluid-solid coupling through the test and simulation of the explosive impact solid square support plate and the charge driven fragments.(2)Carry out the test and simulation of the trolley under the combined action of the explosion shock wave and fragments to verify the accuracy of the model.The honeycomb sandwich structure is selected as the research object,The combined damage caused by shock waves and fragments is greater than the damage caused by a single damage source.Under close explosion conditions,the shock wave acts on the target structure earlier than the fragments.The damage response of the time difference between the explosion shock wave and fragments acting on the target structure is studied.When the explosion shock wave and fragments act on the structure at the same time,the damage caused is the most serious.(3)Through parameterized research methods,the influences of the shape and size of the fragments,the thickness of the sandwich plate,the thickness of the cell honeycomb,the length of the sides,and the position of the explosion point on the combined effect of the shock wave and the fragments are studied.The study found that the square fragments obtain the highest initial velocity and cause the most serious damage;the size of the fragments decreases,and the initial velocity obtained by the fragments increases,and the damage caused is more serious.Changing the side length of the sandwich honeycomb cell has little effect on the damage result.The smaller the thickness of the upper plate,the easier it is for the fragments to pass through the sandwich plate;when only the thickness of the honeycomb cell is changed,the thickness increases and the damage result decreases;try to make the thickness of the upper and lower panels consistent,and the sandwich panel has a higher strength.As the distance between the explosion center and the fragments decreases,the acceleration capability of the shock wave to drive the fragments is gradually reduced,the initial velocity obtained by the fragments also decreases,and the damage to the sandwich panel by the shock waves and fragments is also gradually reduced.