CN109113810B - Engine containment ring with honeycomb-type negative Poisson's ratio structure and manufacturing method - Google Patents

Abstract

The invention discloses an engine containing ring with a honeycomb-type negative Poisson's ratio structure, comprising an inner ring, an outer ring, and an interlayer sandwiched between the inner ring and the outer ring; the interlayer has a plurality of honeycomb-shaped cells , the cells extend in the circumferential direction and have a negative Poisson's ratio in the radial section; the radial section of each cell has two first cell walls and four concave second cell walls, the two The first cell walls extend respectively on two circumferential surfaces concentric with the inner ring and the outer ring, and the first cell walls and the second cell walls are connected and enclosed in a concave hexagonal structure; The two cells are attached to each other through their respective second cell walls. The containment ring has good impact resistance and energy absorption capacity to ensure the reliability of the engine; and also has a good weight reduction effect, which can fully tap the potential of lightweight structural design of aerospace parts. At the same time, the invention also discloses a manufacturing method which is easy to realize and control.

Description

Engine containment ring with honeycomb-type negative Poisson's ratio structure and manufacturing method

technical field

The invention belongs to the field of aero-engines, and specifically designs an engine containment ring with a honeycomb-type negative Poisson's ratio structure and a manufacturing method.

Background technique

With the continuous improvement of the requirements for the use performance of aero-engines such as thrust and rotational speed, the engine blades under high-speed rotation will fail due to foreign object damage, high cycle fatigue, bird strikes, high temperature, material defects, etc. Out of the impact receiver, it is prone to non-containment accidents. High-speed and high-energy non-contained debris may damage the aircraft cabin, fuel tanks, hydraulic pipelines and electrical control lines, posing a serious threat to aviation flight safety. Therefore, the inclusive research of aero-engine is of great significance for improving the safety, reliability and airworthiness of the engine.

The casing surrounding the fan blade is generally called the containment ring. Its function is not only the casing of the airflow channel, but also to contain the fragments of the fan blade in the casing once the fan blade is broken from the root. In the early military and civil aero-engine containment rings, traditional aluminum alloy and titanium alloy materials were generally used. Due to the high strength, good toughness and good protection effect of the material. With the continuous improvement of performance requirements such as engine thrust-to-weight ratio, a single metal material containment ring can no longer meet the needs of lightweight structures. The containment ring of some large engines currently in service mostly uses aluminum alloy as the inner casing, and the surface is milled with grid-like grooves. Dozens of layers of high-strength Kevlar fabric are wrapped around the outside of the aluminum alloy casing, and the outermost layer is made of epoxy resin. Bond curing. This method is significantly lighter than the earlier metal containment rings, but the soft-wall containment receiver structure must have enough external space to allow the high-strength Kevlar fabric to be sufficiently deformed when the debris is impacted.

SUMMARY OF THE INVENTION

Purpose of the invention: In order to overcome the defects of the prior art, the present invention provides an engine containment ring with a honeycomb-type negative Poisson's ratio structure. The deformation of the engine containment ring takes up less space when it is impacted, and has a lighter mass.

Another object of the present invention is to provide a method for manufacturing the above-mentioned engine containment ring.

Technical solution: The engine containment ring with a honeycomb-type negative Poisson's ratio structure according to the present invention includes an inner ring, an outer ring, and an interlayer sandwiched between the inner ring and the outer ring; Each cell extends in the circumferential direction and has a negative Poisson's ratio in its radial cross-section; the radial cross-section of each cell has two first cell walls and four concave second cell walls, so The two first cell walls extend respectively on two circumferential surfaces concentric with the inner ring and the outer ring, and the first cell walls and the second cell walls are connected and enclosed to form a concave hexagonal structure; Two adjacent cells are attached to each other through their respective second cell walls.

Beneficial effects: The engine containment ring adopts a three-layer structure. First, the impact speed is weakened by the inner ring, so that the brittle blades are broken to disperse the impact load and reduce the threat of high-energy debris; The interlayer of Poisson's ratio structure uses its own auxetic effect and honeycomb energy absorption effect. When it is impacted and squeezed by the shrapnel, it immediately shows the property of negative Poisson's ratio, and the material will quickly concentrate in the area where the shrapnel acts, which makes the impacted area. The local strength is significantly increased, so the impact resistance and energy absorption capacity are significantly improved compared with the existing metal containment ring; in addition, the honeycomb structure can embed the fragments of the broken blades that penetrate the inner ring, avoiding the debris to the remaining blades of the rotor. impact, reducing the possibility of secondary damage; and its structural density is significantly reduced, with a good weight reduction effect, which can fully tap the potential of lightweight structural design of aerospace parts; the outer ring plays a rigid support and defense role, making The containment capacity and reliability of the entire containment ring are further improved.

And a kind of manufacturing method of the engine containing ring with honeycomb type negative Poisson's ratio structure according to the present invention is characterized in that, comprises the following steps:

(1) Determine the size of the interlayer and establish a three-dimensional digital model of the interlayer;

(2) Using laser additive manufacturing technology to process the sandwich;

(3) Weld or glue the sandwich between the inner ring and the outer ring.

Beneficial effects: The method adopts laser additive manufacturing technology and conventional welding and bonding technology, which is easy to realize and control, and has high production efficiency.

Description of drawings

Fig. 1 is the structural representation of the engine containing ring with honeycomb type negative Poisson's ratio structure of the present invention;

2 is an enlarged view of a partial cross-sectional structure of the engine containing ring cut along the dotted line in FIG. 1;

Figure 3 is a front view of the partial cross-sectional structure shown in Figure 2; wherein, the A-A line indicates the radial direction;

4 is a schematic diagram of a radial cross-sectional structure of a cell of the present invention;

FIG. 5 is a schematic structural diagram of a spliced engine containment ring in an embodiment.

Detailed ways

Hereinafter, the present invention will be further described in detail with reference to the accompanying drawings.

As shown in FIG. 1 , this embodiment discloses an engine containment ring with a honeycomb-type negative Poisson's ratio structure, including an inner ring 1 , an outer ring 2 , and a sandwich 3 sandwiched between the inner ring 1 and the outer ring 2 . Both the inner ring 1 and the outer ring 2 are made of aluminum alloy or titanium alloy, and the interlayer 3 is made of titanium alloy or aluminum alloy. The thickness of the inner ring 1 is 1-2 mm, and the thickness of the outer ring 2 is 2-5 mm, which can be changed according to the mass, shape and kinetic energy of the missing blades. The thickness of the interlayer 3 is 12mm to ensure that the fragments of the broken blades that penetrate the inner ring have enough space to be embedded in it, avoid the impact of the fragments on the remaining blades of the rotor, reduce the possibility of secondary damage, and effectively improve the casing in the blade. Security after loss.

As shown in FIG. 2 , the interlayer 3 has a plurality of cells 4 arranged staggered in the axial direction in a honeycomb shape, each cell 4 extends in the circumferential direction and is a closed ring, and the radial section of the cell 4 is a negative Poisson’s ratio structure. Compared with traditional metal materials, composite materials, foam materials and honeycomb materials, the structural material has unique mechanical properties, which can significantly improve the impact resistance and energy absorption capacity of the containment ring.

Please refer to FIG. 3 and FIG. 5 for details, wherein the A-A line indicates the radial direction. The radial section of the cell 4 has two first cell walls 41 and four concave second cell walls 42 . The two first cell walls 41 extend respectively on two circumferential surfaces concentric with the inner ring 1 and the outer ring 2 , and the first cell walls 41 and the second cell walls 42 are connected and enclosed in a concave hexagonal structure. The length of the first cell wall 41 is a, the length of the second cell wall 42 is b, the angle between the first cell wall 41 and the second cell wall 42 is θ, and the thicknesses of the first cell wall 41 and the second cell wall 42 are the same. is t. In order to achieve the best impact resistance and energy absorption capacity of the structure, in this embodiment, the length of the first cell wall 41 is twice the length of the second cell wall 42 , wherein the length of the first cell wall 41 is a=4.6 mm, the length b of the second cell wall 42 is 2.3 mm, the angle θ between the first cell wall 41 and the second cell wall 42 is 60°, and the thickness of the first cell wall 41 and the second cell wall 42 is t=0.5 mm .

The arrangement rule of the cells 4 is as follows: two adjacent cells 4 are staggered and attached to each other through a respective second cell wall 42 . The plurality of cells 4 arranged in the radial direction form a row, and the cells 4 in the same row are attached to each other through a respective first cell wall 41 . Further, in order to stabilize the mechanical structure and avoid dislocation, the first cell walls 41 located at both ends of one of the two adjacent rows of cells 4 abut against the inner ring 1 and the outer ring 2 respectively. That is to say, in the same row, the first cell walls 41 at both ends of the head and tail are in contact with the inner ring 1 and the outer ring 2, respectively, or are not in contact with the inner ring 1 and the outer ring 2, so as to avoid the misalignment caused by one end contacting the other end without contact. Structural instability.

The present embodiment also provides a method for manufacturing the above-mentioned engine containment ring, the method comprising the following steps:

(1) Determine the size of the interlayer 3, and establish a three-dimensional digital model of the interlayer 3;

(2) The interlayer 2 is processed and formed using laser additive manufacturing technology;

(3) Weld or glue the interlayer 3 between the inner ring 1 and the outer ring 2 .

The outer ring 2 can adopt the integral structure as shown in FIG. 1 or the split splicing structure as shown in FIG. 5 . When the outer ring 2 is a spliced structure, the outer ring 2 is formed by splicing a plurality of outer ring sub-plates 21 . to make. A plurality of bolt holes are provided on the mounting edge 22 of the edge of the outer ring sub-plate 21 , and the outer ring sub-plates 21 are installed as a whole through bolts 23 . Easy to make and assemble.

Claims (2)

1. a kind of engine with honeycomb type negative poisson's ratio structure contains ring, which is characterized in that including inner ring (1), outer ring (2), the interlayer (3) being clipped between inner ring (1) and outer ring (2)；It is in cellular multiple cell elements (4), institute that the interlayer (3), which has, It states cell element (4) circumferentially and radial section is negative poisson's ratio structure；The radial section of each cell element (4) all has two article The second cell wall (42) of one cell wall (41) and four indents, two first cell walls (41) respectively with the inner ring (1) and Extend on two peripheries of outer ring (2) concentric, the first cell wall (41) and the second cell wall (42) are connected and surrounded in indent six Side shape structure；It is mutually fitted between two interlaced and adjacent cell elements (4) by respective second cell wall (42)；

Multiple cell elements (4) for arranging radially form a column, there is be located at both ends the of a column in two adjacent column cell elements (4) One cell wall (41) is born against in inner ring (1) and outer ring (2)；

The length of first cell wall (41) is twice of the second cell wall (42) length, the first cell wall (41) and the second cell wall (42) Angle be 60 °；

Wherein, the inner ring (1) is with a thickness of 1~2mm, the outer ring (2) with a thickness of 2~5mm, the interlayer (3) with a thickness of 12mm；Outer ring (2) is spliced by muti-piece outer ring daughter board (21), and is opened on the installation side (22) at outer ring plate (21) edge If multiple bolts hole, each outer ring daughter board is mounted to by an entirety by bolt (23)；

The engine contains ring using the method manufacture included the following steps:

(1) size for determining interlayer establishes the three-dimensional digital model of interlayer；

(2) utilize laser gain material manufacturing technology by interlayer machine-shaping；

(3) interlayer is welded or is bonded between inner ring and outer rings.

2. the engine according to claim 1 with honeycomb type negative poisson's ratio structure contains ring, which is characterized in that described Inner ring (1), outer ring (2) and interlayer (3) are made of aluminium alloy or titanium alloy material.