Research On Theory And Test Method Of Strengthening Impact

Before the shipboard equipment is put into use,it is often necessary to carry out the shock resistance assessment,and can be put into use only after passing the assessment.The impact environment provided by the existing impact testing machine can no longer meet the impact environment of some shipboard equipment parts,so it is necessary to carry out more severe impact test for equipment parts.Under the impact environment that the existing impact testing machine can provide,a kind of equipment is added to the impact testing machine,so that the impact environment generated by the impact testing machine can be strengthened and acted on the tested equipment to meet the shock resistance assessment requirements of the tested equipment.This test method is called strengthening impact test method.In this paper,two schemes are provided to realize the enhanced shock test,In this paper,two schemes are provided to realize the strengthening impact test,one of them is the shock amplifier suitable for the half sine wave drop test platform,and the other is the shock amplification base suitable for the positive and negative double wave shock testing machine.A scheme of impact amplifier is proposed to realize the enhanced impact test by using the secondary impact.In addition,the motion analysis of the impact amplifier is carried out,and the motion response of the shock amplifier table during the test is deduced.The finite element model of the impact amplifier strengthening impact test scheme is established.The simulation calculation is carried out through a calculation example.The time history response and the shock response spectrum are used to evaluate the scheme.The acceleration peak value was strengthened by 9.5 times and the constant velocity spectrum value was 1.75 times.Then the influence factors of the impact amplifier scheme,including the initial velocity of the secondary impact,the installation room of the impact amplifier and the load quality of the impact amplifier are studied,and the corresponding influence rules are obtained.Aiming at the scheme of strengthening the impact test on the impact amplification base,the impact amplification base with different quality is tested in different impact directions.The acceleration data analysis shows that the acceleration response of the impact testing machine table is transmitted to the tested equipment through the impact amplification base,the duration of the impact was prolonged,the peak value of the positive wave attenuates and the duration of the negative wave increases.According to the analysis of shock response spectrum,the impact amplification base can realize the amplification of impact environment in the frequency range near the installation frequency of the impact amplification base,and the most obvious strengthening effect is located at the installation frequency of the impact amplification base.In summary,the impact amplifier for drop testing machine can provide higher acceleration peak value,and can strengthen the impact environment in full frequency range.It can meet the requirements of simulating the bubble pulsation impact environment for the impact assessment,and can make up for the lack of small quality of the impact amplifier test equipment,and can strengthen the impact environment near the equipment installation frequency.The two methods can be selected according to the actual situation in the impact test.