CN108953450B

CN108953450B - Impact-resistant energy absorption structure

Info

Publication number: CN108953450B
Application number: CN201810530085.2A
Authority: CN
Inventors: 王成; 徐斌; 徐文龙; 栗皓; 于洪坤
Original assignee: Beijing University of Technology
Current assignee: Beijing University of Technology
Priority date: 2018-05-29
Filing date: 2018-05-29
Publication date: 2020-02-07
Anticipated expiration: 2038-05-29
Also published as: CN108953450A

Abstract

The invention relates to an impact-resistant energy absorption structure, and belongs to the field of protection. The invention adds 3 120-degree uniformly distributed inner tubes in the sandwich middle core tube and arranges the inner tubes in a certain direction. Under the impact action, the middle core tube is crushed firstly, then the upper inner tube is laterally slid and deformed, and a cladding type 3-tube transverse parallel state is formed under the interaction of the middle core tube and the 3 inner tubes and is finally crushed.

Description

Impact-resistant energy absorption structure

Technical Field

The invention relates to an impact-resistant energy absorption structure, and belongs to the field of protection.

Background

With the development of society, the public has increasingly heightened the call for the protection of individuals and public facilities to the human body. The legal sanctions faced by the injury to personnel from mechanical structural failures are also becoming increasingly stringent. Since the 70's of the 20 th century, there has been increasing interest in energy absorbing structures and materials to dissipate the kinetic energy of impacts (or of dynamic loads). The energy absorbing structure is mainly applied to the application fields of improving the crashworthiness of vehicles, the safety protection capability of expressways, the protection capability of industrial accidents, personal safety protection, structural material packaging and the like.

The sandwich composite energy absorption structure formed by the middle core tube structure and the upper and lower cladding plates has the characteristic of irreversible energy conversion, and the reaction force approximately presents a rectangular force-displacement characteristic in the process of generating large deformation of the energy absorption structure. The deformation mode and the energy absorption capacity of the sandwich structure have the characteristics of stability and repeatability, and have higher reliability when the sandwich structure is used for dealing with complex working conditions. Under the condition of adopting aluminum materials as the core pipe and the auxiliary polyurethane composite material, the sandwich structure has the characteristic of light weight and can present higher specific energy absorption capacity. However, the sandwich structure has limited collapse distance due to the characteristics of the geometric structure, the deformation and collapse modes of the core tube are single, the plastic deformation generated by a limited number of plastic hinges is mainly used for absorbing energy, and the specific energy absorption capacity is still limited. At present, a known "sandwich" impact-resistant energy-absorbing structure with the optimal energy-absorbing effect is published in 2017 by Z.L Yu, P.Xue and Z.Chen, and the research structure still has the problems of single crush mode, short crush distance and limited energy-absorbing capacity.

Disclosure of Invention

The invention aims to improve the specific energy absorption capacity of the existing sandwich composite energy absorption structure, and provides an impact-resistant energy absorption structure which can improve the collision resistance of automobiles or improve the safety protection capacity of highways and the industrial accident protection capacity.

The purpose of the invention is realized by the following technical scheme.

An impact-resistant energy absorption structure is characterized in that three hollow pipes are added into a middle core pipe of the existing sandwich energy absorption structure;

the three hollow pipes are uniformly distributed in the middle core pipe at 120 degrees, and the outer surfaces of the hollow pipes are tightly attached to the inner surface of the middle core pipe; ensuring that the plane where the axes of the two hollow pipes are located is parallel to the shroud plate and is positioned close to one side of the shock wave;

the three hollow pipes are uniformly distributed in the middle core pipe at 120 degrees, and the outer surfaces of the hollow pipes are tightly attached to the inner surface of the middle core pipe; the plane where the axes of the two hollow pipes are located and the shroud plate are parallel to each other and located far away from the shock wave to one side, the structure has the similar effect to the structure when the impact speed is lower than 100m/s, and when the impact speed received by the upper shroud plate is higher than 100m/s, the energy absorption effect of the structure is superior to that of the structure;

the materials of the three hollow pipes are the same as those of the middle core pipe;

among the three hollow pipes, polyurethane foam is filled in the independent hollow pipe relatively far away from the shock wave or the equal-weight steel hollow pipe is adopted to enhance the pressure resistance, so that the deformation mode provided by the invention can be fully ensured to be successfully realized, and the energy absorption effect is improved;

the working process is as follows: when the shock wave reaches the upper web and propagates towards the "sandwich" composite energy absorbing structure, the intermediate core tube begins to crush first. At the initial stage of crushing of the middle core pipe, the three hollow pipes do not deform obviously, and the two hollow pipes close to the upper shroud plate slide to the left and right along the outer surfaces of the single hollow pipes at the lower part. Along with the continuous crushing of the middle core pipe, the two upper hollow pipes begin to crush under the dual action of the single lower hollow pipe and the middle core pipe, and the left side surface and the right side surface of the single lower hollow pipe deform under the extrusion action of the two upper hollow pipes, so that the height of the single hollow pipe is increased. With the continuous interaction of the middle core pipe and the three hollow pipes, the three hollow pipes finally present a parallel mode in the middle core pipe, the inner surface of the middle core pipe is fully contacted with the outer surfaces of the three hollow pipes, and the annular parts of the middle core pipe and the hollow pipes are uniformly deformed, so that the number of plastic hinges and the crushing angle are increased to the maximum extent. Finally, the middle core tube structure and the hollow tube structure are fully crushed to reach the energy absorption limit of the structure.

Advantageous effects

1. In order to improve the specific energy absorption capacity of the sandwich composite energy absorption structure, the invention provides a novel sandwich composite structure, the specific energy absorption capacity of the sandwich structure is improved by designing and modifying the middle core tube structure, and compared with the research results of Z.L Yu, P.Xue and Z.Chen, the research specific energy absorption capacity can be improved by 5%.

2. The design of a sandwich composite structure provides a novel pipe structure collapse mode, increases the plastic hinge quantity and the plastic hinge rotation angle of the sandwich structure, and increases the plastic deformation energy. Polyurethane foam is filled in the single hollow pipe or the equal-mass steel hollow pipe is used instead, the rigidity of the hollow pipe is enhanced, the smooth realization of the collapse mode proposed by the research is fully ensured, and the energy absorption capacity of the hollow pipe can be improved by 5-10% compared with the research results of Z.L Yu, P.Xue and Z.Chen.

Drawings

FIG. 1 is a schematic view of an impact energy absorbing structure of example 1 of the present invention;

FIG. 2 illustrates the deformation process of the "sandwich" composite energy absorbing structure of this example 1; wherein FIG. 2a is the initial state of the "sandwich" structure; FIG. 2b shows the middle core tube starting to crush due to impact, and the two upper hollow tubes sliding to the left and right along the outer surfaces of the single bottom hollow tubes; FIG. 2c shows the upper two hollow tubes having been fully slid toward the bottom single hollow tube on both sides, and the three hollow tubes are initially formed in a juxtaposed state; fig. 2d shows that the three hollow pipes are completely in a horizontal parallel state, the external middle core pipe completely covers the three hollow pipes inside to form a stable structure similar to a triangular support of a corrugated paper interlayer, and the overall structure is further crushed and finally fails to reach the energy absorption limit along with the further action of external impact on the energy absorption structure.

The composite plate comprises a base plate, a first hollow pipe, a second hollow pipe, a third hollow pipe and a lower covering plate, wherein the base plate comprises 1-an upper covering plate, 2-a middle core pipe, 3-a first hollow pipe, 4-a second hollow pipe, 5-a third hollow pipe and 6-a lower covering plate.

Detailed Description

The invention is further described with reference to the following figures and examples.

Example 1

An impact-resistant energy absorbing structure comprising: the core tube comprises an upper cladding plate 1, a middle core tube 2, a first hollow tube 3, a second hollow tube 4, a third hollow tube 5 and a lower cladding plate 6; the middle core tube 2 is positioned between the upper cladding plate 1 and the lower cladding plate 6; the first hollow pipe 3, the second hollow pipe 4 and the third hollow pipe 5 are positioned in the middle of the middle core pipe 2; namely, three hollow pipes are added into a middle core pipe of the existing sandwich energy absorption structure; the overall structural installation is as shown in figure 1.

Connection relation:

the upper and lower skin plates 1, 6 are steel structures with dimensions of 40 x 20 x 2 mm. The length of the middle core tube 2 is 20mm, the outer diameter is 40mm, and the thickness is 1.6 mm. The thickness of the first hollow pipe 3, the thickness of the second hollow pipe 4 and the thickness of the third hollow pipe 5 are all 1.2mm, the length is 20mm, the outer diameter is 14.7mm, and the first hollow pipe 3, the second hollow pipe 4 and the third hollow pipe 5 are uniformly distributed and installed and then are in close contact with the middle core pipe 2. The lower shroud 6 has dimensions of 60 x 20 x 2 mm.

The first hollow pipe 3, the second hollow pipe 4 and the third hollow pipe 5 are uniformly distributed in the middle core pipe 2 at 120 degrees, and the outer surfaces of the first hollow pipe 3, the second hollow pipe 4 and the third hollow pipe are tightly attached to the inner surface of the middle core pipe 2; ensuring that the planes of the axes of the first hollow pipe 3 and the second hollow pipe 4 are parallel to the shroud plate and are positioned close to the incoming side of the shock wave;

the working process is as follows:

the upper cladding plate 1 receives shock wave impact or structural impact, and the shock wave is transmitted to the sandwich structure from the upper cladding plate 1 to deform the structure. Under the action of the shock wave, the middle core tube 2 begins to crush firstly, the crushing is initial, and under the combined action of the middle core tube 2 and the third hollow tube 5, the first hollow tube 3 and the second hollow tube 4 slide laterally and slightly deform. As the intermediate core tube 2 is further crushed, the first hollow tube 3 and the second hollow tube 4 start crushing deformation. The third hollow tube 5 is extruded and deformed by the extruding action of the first hollow tube 3 and the second hollow tube 4 on both sides, and the height thereof starts to increase and finally comes into contact with the upper surface of the inner side of the intermediate core tube 2. And then the first hollow tube 3, the second hollow tube 4 and the third hollow tube 5 are uniformly arranged in the middle core tube 2 to form a transverse side-by-side mode, the middle core tube 2 is tightly attached to the first hollow tube 3, the second hollow tube 4 and the third hollow tube 5, and a triangular support stable structure similar to a corrugated paper middle interlayer is formed. If the shock wave intensity is large enough, the closely attached middle core tube 2 and the first hollow tube 3, the second hollow tube 4 and the third hollow tube 5 continuously deform and finally collapse until the whole sandwich structure reaches the maximum energy absorption value.

The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. An impact-resistant energy absorbing structure characterized by: the method comprises the following steps: the upper cladding plate, the middle core pipe, the first hollow pipe, the second hollow pipe, the third hollow pipe and the lower cladding plate; the middle core pipe is positioned between the upper cladding plate and the lower cladding plate; the first hollow pipe, the second hollow pipe and the third hollow pipe are positioned in the middle of the middle core pipe and are called a sandwich composite energy absorption structure;

the energy absorption process of the structure is as follows: when the shock wave reaches the upper web plate and is transmitted to the sandwich composite energy absorption structure, the middle core pipe begins to crush at first; at the initial stage of crushing of the middle core pipe, the three hollow pipes do not deform obviously, and the two hollow pipes close to the upper shroud plate slide to the left and right along the outer surfaces of the single hollow pipes at the lower part; along with the continuous crushing of the middle core pipe, the two upper hollow pipes begin to crush under the dual action of the single lower hollow pipe and the middle core pipe, and the left side surface and the right side surface of the single lower hollow pipe deform under the extrusion action of the two upper hollow pipes, so that the height of the single hollow pipe is increased; with the continuous interaction of the middle core pipe and the three hollow pipes, the three hollow pipes finally present a parallel mode in the middle core pipe, the inner surface of the middle core pipe is fully contacted with the outer surfaces of the three hollow pipes, and the annular parts of the middle core pipe and the hollow pipes are uniformly deformed, so that the number of plastic hinges and the crushing angle are increased to the maximum extent; finally, the middle core tube structure and the hollow tube structure are fully crushed to reach the energy absorption limit of the structure.

2. An impact-resistant energy absorbing structure in accordance with claim 1, wherein: the three hollow pipes are uniformly distributed in the middle core pipe at 120 degrees, and the outer surfaces of the first hollow pipe, the second hollow pipe and the third hollow pipe are tightly attached to the inner surface of the middle core pipe; the plane of the axes of the two hollow pipes is parallel to the shroud plate and is located close to the incoming side of the shock wave.

3. An impact-resistant energy absorbing structure according to claim 1 or 2, wherein: the materials of the first hollow pipe, the second hollow pipe and the third hollow pipe are the same as the material of the middle core pipe.

4. An impact-resistant energy absorbing structure according to claim 1 or 2, wherein: and polyurethane foam or an equiheavy steel hollow pipe is filled in the independent hollow pipe relatively far away from the shock wave among the first hollow pipe, the second hollow pipe and the third hollow pipe.