CN102431180A - Manufacturing method of partially cured Z-pin - Google Patents

Abstract

The invention relates to an implantation method of a partially cured composite material Z-pin. The method is characterized in that: 1. the process consists of manufacturing and implantation of partially cured Z-pin; 2. the manufacturing process includes establishing a preparation parameter database of partially cured Z-pin, and each record of the database includes a Z-pin material, preparation parameters, a curing degree and modulus of the prepared Z-pin; the relation between a smallest Z-pin modulus needed for implantation of a selected prepreg material and the modulus scope of partially cured Z-pin in the above database is calculated so as to choose appropriate manufacturing parameters; 3. freezing treatment is conducted to the Z-pin which does not meet the implantation requirement in terms of rigidity. The Z-pin has a low initial curing degree, and when implanted into the prepreg, the Z-pin and the matrix resin of the prepreg can undergo a crosslinking reaction during curing, and a strong chemical bonding force can enhance the chemical bonding strength between the Z-pin and a panel. Compared with completely cured Z-pin reinforced composite materials, the Z-pin reinforced composite material of the invention has substantially improved mechanical property.

Description

Not exclusively solidify the manufacturing approach of Z-pin

Affiliated technical field

The present invention relates to the manufacturing approach of composite Z-pin, it is characterized in that incomplete curing, belong to the method for composite material technical field.

Background technology

The Z-pin technology is the thin bar Z-pin of needle-like to be implanted in the repeatedly good prepreg in shop form three-dimensional the enhancing; Overall structure through co-curing formation; Referring to list of references " Review of Z-pinned composite laminates " (Mouritz A P; Application Science and Manufacturing, 2007,38/12).This technology can obviously be improved the interlaminal toughness of composite laminated plate, and has simple to operately, and designability is strong and be easy to the characteristics of global formation, and application prospect is extensive, particularly aspect Aero-Space, has the potentiality of alternative metals material.But,, utilize Z-pin reinforced composite materials that present manufacturing technology obtains when bearing load according to present reported in literature and evidence; Usually destroy with the form of Z-pin pull-off from panel material, therefore, the bond strength of Z-pin and panel is the key factor of restriction Z-pin performance reinforced effects; Referring to list of references " Experimental study on Z-pin bridging law by pull-out test " (Dai S C, Yan W Y, Liu H Y; Et al; Composite Science and Technology, 2004,64/16).

Summary of the invention

The objective of the invention is to; Improve the deficiency of existing Z-pin manufacturing technology and method; The manufacturing approach of a kind of incomplete curing Z-pin is provided,, solves the difficult problem that Z-pin reinforced composite Z-pin when carrying is prone to pull-off to strengthen Z-pin and to be enhanced the chemical bond between laminate.

The method for implantation of a kind of incomplete curing Z-pin comprises the preparation process of Z-pin and the implantation process of Z-pin; It is characterized in that:

Above-mentioned Z-pin refers to that curing degree is 50～80% incomplete curing Z-pin;

The preparation process of not exclusively solidifying Z-pin is following:

(1), select the used resin matrix of Z-pin, set up the preparation parameter database that not exclusively solidifies Z-pin, the curing degree that wherein not exclusively solidifies Z-pin is 50～80% according to the material system of prepreg;

Every record of this database comprises: the modulus of the curing degree of Z-pin material, preparation parameter, prepared Z-pin, prepared Z-pin; Above-mentioned preparation parameter comprises: glue groove temperature, mold temperature, drying tunnel temperature, pultrusion speed;

In all records of this database, the maximum meter of prepared Z-pin modulus is made E1, and minimum of a value is calculated E0;

(2), when utilizing the Z-pin testpieces to measure ultrasonic implantations, the resistance F of the prepreg that Z-pin receives, the minimum pressure F that definite thus ultrasonic implanting gun need provide _Min

According to one section hold-down support, the strut buckling formula under one section free situation can calculate the minimum modulus E that accomplishes the required Z-pin of ultrasonic implantation _Min

$E_{\min }=\frac{F_{\min }{\left(2l\right)}^2}{{\mathrm{\π}}^{2}I}$

In the formula; I is a moment of inertia; L is the length that Z-pin is exposed at the carrier foam segment, sees among Fig. 2 to identify;

(3) utilize (2) to go on foot the E that obtains _MinIn the database of (1) step foundation, inquire about, carry out subsequent treatment according to Query Result:

(3-1) as E0＜E _MinDuring＜E1, select E in the database _MinOr Z-pin is not exclusively solidified in the corresponding preparation parameter preparation of its closest value;

(3-2) work as E _MinDuring＜E0, select the preparation parameter preparation that E0 is corresponding in the database not exclusively to solidify Z-pin;

(3-3) work as E _MinDuring＞E1, select the preparation parameter preparation that E1 is corresponding in the database not exclusively to solidify Z-pin; Incomplete curing Z-pin to preparation carries out freezing processing then.

According to one's analysis, the adhesion of Z-pin and panel comprises physical bond and chemical bond, and combining between present completely crued Z-pin and the panel is that physical bond plays a crucial role, and mainly is frictional force and intermolecular normal form adhesion.And not exclusively solidify between Z-pin and the panel main by chemical bond; Z-pin and panel base interlaminar resin generation cross-linking reaction; Form covalent bonds in a large amount of molecules, the bond strength that on macroscopic view, shows as Z-pin and panel improves greatly, makes Z-pin from panel, be difficult to pull-off.

The principle of not exclusively solidifying the Z-pin reinforced composite is following, and (1) according to the test experience, the definition curing degree is that the Z-pin of 40%-80% is semi-solid preparation Z-pin, and according to different Z-pin resin matrixes, this scope needs to adjust slightly at the 40%-80% annex.Z-pin and the chemical bond between the panel according to this paper provides are theoretical, and the curing degree of Z-pin is low more, and then the chemical bond with panel is strong more, but low if the curing degree minimum was set, and causes resin to preserve the part flowability, then can not realize the shaping of Z-pin.(1) when co-curing; Seepage flow takes place in the big molecule of resin uncured among the Z-pin under diffusion; With cross-linking reaction takes place after the panel base mixed with resin; Form covalent bond in a large amount of molecules, make the strong chemical bond effect of generation between Z-pin and panel, to improve both interface bond strengths; (2), the raising of the reduction of each section of pultrusion temperature and pultrusion speed all can reduce the curing degree of Z-pin.In theory, along with the reduction of curing degree, the modulus of not exclusively solidifying Z-pin reduces.When rigidity is reduced to a certain degree; Can guarantee cylindrical outer shape though not exclusively solidify Z-pin; But can not satisfy the prepreg that vertical implantation smoothly is enhanced, utilize K cryogenic treatment can freeze the macromolecular chain in the resin among the Z-pin, reduce the movable property of strand; Improve the rigidity of Z-pin, carry out smoothly with what guarantee to implant.

The advantage of not exclusively solidifying Z-pin is: (1) has reduced the temperature of mould with the back drying tunnel, has reduced energy resource consumption, has reduced cost.(2) improved pultrusion speed, improved production efficiency, implanted water operation for the pultrusion of Z-pin possibility is provided.(3) not exclusively solidify the Z-pin reinforced composite materials and compare and solidify the Z-pin reinforced composite materials fully, performance and interlayer performance in the face (comprise I type interlayer faults toughness, II type interlayer faults toughness and impact afterwards compression performance etc.) are significantly improved.

Description of drawings

Fig. 1 is Z-pin pultrusion process and equipment sketch map;

Fig. 2 is the ultrasonic implantation sketch map of Z-pin.

Fig. 3 is the bridge rate test load-displacement curve of 70% and 100% curing Z-pin enhancement layer plywood.

Fig. 4 be 70% and 100% solidify Z-pin enhancement layer plywood I type interlayer faults toughness test column diagram as a result;

Label title among the figure: 1, put yarn feeding device, 2, the fibre guide device, 3, gumming device, 4, pultrusion die, 5, the back solidification equipment, 6, draw-gear, 7, wrap-up, 8, the carrier foam, 9, prepreg.

The specific embodiment

This embodiment explains the preparation method of incomplete curing Z-pin provided by the invention.

(1) T300 silvalin tube is installed on the yarn feeding device of putting in the accompanying drawing 1, the yarn tube guarantees that by Tension Control impregnation is abundant.Fiber passes fibre guide device, gumming device, mould and the back drying tunnel in the accompanying drawing 1 successively.Be placed with low viscosity resin in the glue groove, can heat to reduce resin viscosity the glue groove.Be soaked with fiber preformed in mould of resin, simultaneously, cross-linking reaction begins to carry out.Back drying tunnel temperature is the key factor of control curing degree, and curing reaction mainly occurs in the drying tunnel of back.Final through draw-gear, by two pairs of tangent rubber rollers tractive force is provided.

(2) according to choose 70% and 100% curing degree with reference to the pultrusion parameter of used FW125 epoxy resin and the database of corresponding Z-pin curing degree two groups, the pultrusion parameter sees the following form.

(3) group 1 is not exclusively solidified Z-pin and is solidified Z-pin fully with group 2 and implant in the prepreg that the shop is repeatedly good in advance, carries out co-curing, obtains two groups of Z-pin enhancement layer plywood.

Respectively two groups of Z-pin enhancement layer plywood are carried out test of bridge rate and I type interlayer faults toughness test according to the method in the document " Experimental study on z-pin bridging law by pullout test " and " interlayer faults toughness test method part 1 under the carbon fibre composite laminate hygrothermal environment: I type interlayer faults toughness test method "; Obtain the result and see Fig. 2 and Fig. 3; From Fig. 2, obviously can find out; Solidify the required power of Z-pin pull-off from panel with 70% and be higher than the required power of 100% curing Z-pin pull-off far away, show among Fig. 3 that 70% curing Z-pin enhancement layer plywood compares 100% and solidifies Z-pin enhancement layer plywood I type interlayer faults toughness value G _ICImprove 39%, reinforced effects is obvious.

Claims (1)

1. a method for implantation that not exclusively solidifies Z-pin comprises the preparation process of Z-pin and the implantation process of Z-pin; It is characterized in that:

Above-mentioned Z-pin refers to that curing degree is 40～80% incomplete curing Z-pin;

The preparation process of not exclusively solidifying Z-pin is following:

(1), select the used resin matrix of Z-pin, set up the preparation parameter database that not exclusively solidifies Z-pin, the curing degree that wherein not exclusively solidifies Z-pin is 50～80% according to the material system of prepreg;

Every record of this database comprises: the modulus of the curing degree of Z-pin material, preparation parameter, prepared Z-pin, prepared Z-pin; Above-mentioned preparation parameter comprises: glue groove temperature, mold temperature, drying tunnel temperature, pultrusion speed;

In all records of this database, the maximum meter of prepared Z-pin modulus is made E ₁, minimum of a value is calculated E ₀

(2), when utilizing the Z-pin testpieces to measure ultrasonic implantations, the resistance F of the prepreg that Z-pin receives, the minimum pressure F that definite thus ultrasonic implanting gun need provide _Min

According to one section hold-down support, the strut buckling formula under one section free situation can calculate the minimum modulus E that accomplishes the required Z-pin of ultrasonic implantation _Min

$E_{\min }=\frac{F_{\min }{\left(2l\right)}^2}{{\mathrm{\π}}^{2}I}$

In the formula, I is a moment of inertia; L is the length that Z-pin is exposed at the carrier foam segment, sees among Fig. 2 to identify;

(3) utilize (2) to go on foot the E that obtains _MinIn the database of (1) step foundation, inquire about, carry out subsequent treatment according to Query Result:

(3-1) work as E ₀＜E _Min＜E ₁The time, select E in the database _MinOr Z-pin is not exclusively solidified in the corresponding preparation parameter preparation of its closest value;

(3-2) work as E _Min＜E ₀The time, select E in the database ₀Z-pin is not exclusively solidified in corresponding preparation parameter preparation;

(3-3) work as E _Min＞E ₁The time, select E in the database ₁Z-pin is not exclusively solidified in corresponding preparation parameter preparation; Incomplete curing Z-pin to preparation carries out freezing processing then.

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