| On a global scale,fall accidents from heights occur from time to time,and the resulting casualties and economic losses are immeasurable.There are many factors that cause frequent fall accidents from heights,and the lack of effective fall protection equipment is one of the most important reasons.As an important component of the high-altitude fall protection system,the buffer can absorb part of the impact energy when a person falls,reduce the impact force,and ensure that the energy is no longer transmitted to the human body,thereby protecting the life of the person.Among them,the core component of the buffer that plays the role of absorbing and dissipating energy and reducing braking force is the tearing belt.Therefore,this topic focuses on the problem of less research on the preparation process of the tear tape and lack of systematic research on energy absorber performance.The double needle and double weft webbing technology is combined with the electronic jacquard technology to prepare the tear tape of different specifications and made by sewing technology.Different specifications of energy absorber were used to study the influence of different tearing bands and different process parameters on the static and dynamic mechanical properties of energy absorber.Through research,the following conclusions are drawn:(1)The basic structure of the webbing part of the tearing belt is selected as 2/2 twill weave,and the connecting yarn is interwoven with a plain weave.The tearing belt can achieve tearing and meet the requirements of buffering and absorbing energy.The maximum weft density of the tear tape can be 2000 D.When the density of the weft yarn exceeds 2000 D,the machine cannot pick the weft normally.The weft density of the tear tape is greatly affected by the density of the weft yarn and the number of yarns in the warp direction,and the general range is 5.2/cm-6.7/cm.(2)Through exploring the influencing factors of the static mechanical properties of the tearing belt-load-bearing belt composite buffer,the results show that: when the tearing belt does not accidentally crack,the initial deformation is mainly affected by the manual operation during the sewing process;The opening force is less affected by the weft density and weft density of the tearing belt,which is mainly determined by the number of connecting yarns and the breaking strength;the strength of the webbing and the sewing process have a greater impact on the static load performance of the buffer,and the zigzag reinforcement stitch is adopted The high-strength webbing pattern,the selection of high-strength webbing,and the slightly increased length of the part of the tear tape can greatly improve the static load performance of the buffer.The current maximum strength value of the sample is 29080 N.(3)Through the dynamic mechanical performance test of energy absorber of different specifications,different structures and different lengths,it is concluded that the specifications of the tear band,the structure of the buffer,and the permanent deformation of the buffer affect the dynamic mechanical performance of the buffer Larger.In the case of the same drop height and the same structure,the test and analysis show that the number of connected yarns and the specifications of the connected yarns in the tear belt have a greater impact on the dynamic mechanical properties of the buffer.When the braking distance of the tearing belt is less than or equal to the maximum expansion length of the buffer,the tearing belt can play a good buffering effect on the entire falling process.At this time,the braking force of the buffer mainly depends on the opening process of the tearing belt When the braking distance of the tear tape is greater than the maximum deployment length of the buffer,when the tear tape tears normally,only the distance within the deployment length can be braked.For those that fail to brake In part,the force will directly act on the connection point,and the braking force will be greatly increased. |
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