阅读说明：本技术 一种割裂式吸能结构的设计方法 (Design method of fracture type energy absorption structure ) 是由 姜士鸿 王成强 金辉 王雷 于 2021-09-07 设计创作，主要内容包括：一种割裂式吸能结构的设计方法,该吸能结构能够通过复材吸能管纤维绕线、层数、线径和材料的不同,实现吸能量的调整和缓冲力变化。同时,该复材吸能结构内部具有凸起的切断刀,用于割裂复材纤维,因此与金属刨削吸能,金属胀管、缩管吸能器比,可以实现变力值吸能。材料密度小,质量轻。该吸能结构具有吸能量可控,缓冲力设计方便的特点。(A design method of a fracture type energy absorption structure can realize adjustment of energy absorption and change of buffer force through different fiber winding, layer number, line diameter and materials of a composite material energy absorption pipe. Meanwhile, the composite energy absorption structure is internally provided with a raised cutting knife for cutting and cracking the composite fiber, so that the energy absorption with variable force value can be realized compared with a metal planing energy absorption device, a metal expansion pipe and a metal contraction pipe energy absorber. The material has low density and light weight. The energy absorption structure has the characteristics of controllable energy absorption and convenient design of buffering force.)

1. A design method of a fracture type energy absorption structure is characterized by comprising the following steps: the energy absorption structure comprises a composite energy absorption pipe and a mounting flange, wherein the composite energy absorption pipe is mainly made of a material formed by winding fibers; the mounting flange is a metal piece, the inner wall of the mounting flange is provided with a plurality of raised cutting knives, the knives are tough and upward, and the composite energy absorption pipe is arranged in the mounting flange and is in clearance sliding fit with the mounting flange; the design method comprises the following steps:

the first step is as follows: determining the buffering force and the designed energy absorption stroke of the energy absorber according to five technical parameters of customer input energy absorption, the maximum energy absorption stroke, the installation size, special working conditions and the maximum peak force; the energy absorption is determined by the factors of train marshalling, running speed and collision working condition, the installation size is determined by the train body structure, the maximum energy absorption stroke is realized by the train body structure and the collision resistance design process of the train, and the special working condition is determined by the train running condition; the maximum peak force is determined according to the maximum force value borne by the train structure;

the design parameters follow the following basic formula:

w＝Fh＝nfh

w energy of energy absorption

F: energy absorber buffering power

h: energy-absorbing stroke

n is the number of cutting-off tools

f: force value of single cutting knife cutting composite material fiber;

the second step is that: primarily selecting the fiber types, the diameters, the cutter numbers and the cutting edge structures according to the calculated buffer force of the energy absorber;

the third step: primarily selecting the number of the cutters and the cutting edge structure according to the calculated buffer force of the energy absorber; and the force value of the composite material fiber cut by the single cutting knife is verified through tests;

the fourth step: then, the fiber types and diameters are selected according to the material performance and the manufacturing process; finally, test verification is carried out, wherein the force values are mainly force values when different fiber diameters and numbers are cut off;

the fifth step: determining the overall dimension of the composite pipe according to the installation dimension, then determining the number of fiber layers, the fiber diameter and the number along the stroke direction according to the fourth step, and then manufacturing the composite energy absorption pipe by a winding method;

and a sixth step: carrying out installation test according to the input requirement;

the seventh step: if the performance meets the requirements, the design and development are completed; and if the performance is not satisfied, repeating the third step to the sixth step to design the performance until the product performance is satisfied.

2. The design method of a rip energy absorption structure according to claim 1, wherein: the special working conditions refer to high and low temperature, vibration and humidity.

3. The design method of a rip energy absorption structure according to claim 1, wherein: the section of the cutting knife is in a house shape with a herringbone upper part and a square lower part.

4. The design method of a rip energy absorption structure according to claim 1, wherein: the cutting-off cutters are uniformly arranged on the periphery of the inner wall of the mounting flange.

Technical Field

The invention belongs to the technical field of rail vehicle manufacturing, and particularly relates to a design method of an energy absorption structure.

Background

The passive safety research is carried out on the railway vehicle, and a proper energy absorber is adopted, so that the collision resistance of the train is improved, and the accident loss is minimized. The train impact resistance means: in the collision process, the bearing capacity and the deformation form of the train structure and the capacity of the train structure for absorbing the collision kinetic energy are integrated. The train is required to deform at a secondary part of the train structure in order according to the will of people under a certain impact speed, so that the impact acceleration can be effectively reduced while more impact kinetic energy is absorbed, and the manned part of the train body structure can provide living space for drivers and passengers in the passenger room, thereby reducing the harm brought by the collision to people. The anti-collision train is designed by arranging a certain deformation area at a specific part of a train body, and installing an energy absorber and an anti-climbing device to absorb kinetic energy of the train during collision as much as possible, reduce collision acting force and prevent the occurrence of train overlapping accidents, thereby reducing casualties to the maximum extent.

At present, a common energy absorption structure of a railway vehicle is a honeycomb type energy absorber, and according to the energy absorption energy required by customers, the factors of large energy absorber and the like, the energy absorption structure is converted into the energy absorption force value, the honeycomb sectional area and the energy absorption stroke of a honeycomb through calculation. Because all the cross-sectional shapes of the honeycomb energy absorption directions are the same, the absorption capacity value of the honeycomb in the energy absorption stroke is basically unchanged. The structure has the advantages of simple structure and convenient design; the disadvantage is that the peak forces occurring at the beginning of the energy absorption may cause damage to the vehicle body. Therefore, the research on an energy absorption structure with adjustable energy absorption value tends to be great.

Disclosure of Invention

The invention aims to provide a design method of a splitting type energy absorption structure with adjustable energy absorption force.

In order to achieve the purpose, the invention provides a design method of a fracture type energy absorption structure, which is characterized by comprising the following steps of: the energy absorption structure comprises a composite energy absorption pipe and a mounting flange, wherein the composite energy absorption pipe is mainly made of a material formed by winding fibers; the mounting flange is a metal piece, the inner wall of the mounting flange is provided with a plurality of raised cutting knives, the knives are tough and upward, the composite energy absorption pipe is arranged in the mounting flange and positioned above the cutting knives, and the composite energy absorption pipe is in clearance sliding fit with the mounting flange; the design method comprises the following steps:

the first step is as follows: determining the buffering force and designing the energy absorption stroke of the energy absorber according to five technical parameters of customer input energy absorption, energy absorption stroke, installation size, special working conditions and maximum peak force; the energy absorption is determined by the factors of train marshalling, running speed and collision working condition, the installation size is determined by the train body structure, the energy absorption stroke is realized by the train body structure and the design process of collision resistance of the train, and the special working condition is determined by the train running condition, namely high temperature, low temperature, vibration and humidity; the maximum peak force is determined according to the maximum force value borne by the train structure;

the design parameters follow the following basic formula:

w＝Fh＝nfh

w energy of energy absorption

F: energy absorber buffering power

h: energy-absorbing stroke

n is the number of cutting-off tools

f: force value of single cutting knife cutting composite material fiber;

the second step is that: primarily selecting the fiber types, the diameters, the cutter numbers and the cutting edge structures according to the calculated buffer force of the energy absorber;

the third step: cutting the fiber by using a cutting knife, determining a force value for cutting the composite fiber, and repeating the test for multiple times to determine the consistency;

the fourth step: determining the quantity of the composite fibers cut by the cutting knife according to the buffer force of the energy absorber and the force value of the composite fibers cut by the cutting knife obtained in the second step and the third step;

the fifth step: determining the overall dimension of the composite energy-absorbing pipe according to the installation dimension, and then manufacturing the composite energy-absorbing pipe by a winding method according to the determined energy-absorbing stroke and the determined fiber quantity;

and a sixth step: carrying out installation test according to the input requirement;

the seventh step: if the performance meets the requirements, the design and development are completed; if the performance is not satisfied, repeating the steps from the second step to the sixth step to iterate the cutting knife structure and the auxiliary material fiber type, diameter and winding method until the performance of the product is satisfied.

The section of the cutting knife is in a house shape with a herringbone upper part and a square lower part.

The cutting-off cutters are uniformly arranged on the periphery of the inner wall of the mounting flange.

Compared with the prior art, the invention has the following advantages and progresses:

1. because the main energy absorption part is made of composite materials and has low material density, compared with a metal energy absorber, the energy absorber has the characteristic of light weight.

2. The composite material energy absorption structure can realize energy absorption by cutting composite material fibers according to actual working conditions, and realizes adjustment of energy absorption and change of buffer force by the difference of fiber winding, layer number, wire diameter and materials. Therefore, compared with a metal planing energy absorber and a metal expansion pipe and contraction pipe energy absorber, the energy absorber can realize variable force value energy absorption.

3. The composite material energy absorption structure is internally provided with a raised cutting knife for cutting and cracking the composite material fiber so as to realize energy absorption. The energy absorption has the characteristics of controllable energy absorption and convenient design of buffering force.

Drawings

FIG. 1 is a schematic view of the energy absorbing structure;

FIG. 2 is a cross-sectional view taken along line A-A of FIG. 1;

FIG. 3 is a top view of FIG. 1;

FIG. 4 is a schematic view showing the positional relationship between a mounting flange and a cutting blade;

FIG. 5 is a flow chart of a design of the energy absorbing structure.

Detailed Description

Referring to fig. 1-5, the energy absorption structure of the invention comprises a composite energy absorption pipe 1 and a mounting flange 2, wherein the composite material is mainly a fiber reinforced material formed by winding fibers; the mounting flange 2 is a metal piece. A plurality of raised cutting knives 3 are uniformly arranged on the periphery of the inner wall of the mounting flange 2, the knives are tough and upward, the composite energy absorption pipe is arranged in the mounting flange and positioned above the cutting knives, and the composite energy absorption pipe is in clearance sliding fit with the mounting flange. The section of the cutting knife is in a house shape with a herringbone upper part and a square lower part, the cutting knife 3 is arranged on the inner wall of the mounting flange 2, and the composite energy absorption pipe is in clearance sliding fit with the mounting flange; the design method comprises the following steps:

the first step is as follows: according to five technical parameters of customer input energy absorption, maximum energy absorption stroke, installation size, special working conditions (high and low temperature, vibration and humidity) and maximum peak force; determining the buffer force and the design energy absorption stroke of the energy absorber according to the formula w, Fh and nfh;

the second step is that: primarily selecting the fiber types, the diameters, the cutter numbers and the cutting edge structures according to the calculated buffer force of the energy absorber;

the third step: cutting the fiber by using a cutting knife, determining the force value for cutting the composite fiber, and repeating the test for more than 5 times to determine the consistency;

the fourth step: determining the quantity of the composite fibers cut by the cutting knife according to the buffer force of the energy absorber and the force value of the composite fibers cut by the cutting knife obtained in the second step and the third step;

the fifth step: determining the overall dimension of the composite energy-absorbing pipe according to the installation dimension, and then manufacturing the composite energy-absorbing pipe by a winding method according to the determined energy-absorbing stroke and the determined fiber quantity;

and a sixth step: carrying out installation test according to the input requirement;

the seventh step: if the performance meets the requirements, the design and development are completed; if the performance is not satisfied, repeating the steps from the second step to the sixth step to iterate the cutting knife structure and the auxiliary material fiber type, diameter and winding method until the performance of the product is satisfied.

When the energy-absorbing composite material pipe works, the mounting flange is connected to the front end of the vehicle body and fixed, when the composite material energy-absorbing pipe is impacted, the composite material energy-absorbing pipe retreats under the guiding action of the mounting flange, and the composite material fiber in the composite material energy-absorbing pipe is cut under the action of the cutting knife, so that energy absorption is realized.