Composite pultrusion bar tensile test sample and manufacturing mold

Abstract

The utility model discloses a tensile test sample for a composite pultrusion bar and a manufacturing die, and the tensile test sample for the composite pultrusion bar comprises a bar body and a reinforcing layer, the reinforcing layer is formed by winding a fast curing fabric prepreg, an adhesive film or a fabric impregnated with fast curing resin at the two ends of the bar body and performing pressurization curing molding. The device can be used for quickly and efficiently preparing the tensile test sample of the composite pultrusion bar, and can effectively avoid abnormal damage such as bar body clamping and cracking of the sample during testing.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of composite material tensile test, specifically relates to a kind of composite material pultruded bar tensile test sample and production mould. BACKGROUND

[0002] In order to detect the tensile properties of composite material pultruded bar (composite material round bar, threaded bar, anchor rod) (hereinafter referred to as round bar, threaded bar, anchor rod), the bar needs to be tensile tested, and if the bar is directly installed on the testing equipment for tensile testing, the testing equipment chuck is metal material, and the bar is made of unidirectional fiber, so the bar will be clamped and cracked, and abnormal damage will occur during testing, resulting in testing failure. Usually, the anchoring method is used to make tensile test sample, but this method takes a long time to make tensile test sample and is only suitable for making threaded bar and anchor rod tensile test sample, not suitable for making round bar tensile test sample. The anchoring method takes a long time to make tensile test sample, mainly because the bonding agent needs to be poured twice, first the bar is vertically placed in the steel pipe, then the bonding agent is poured, and the other end of the bar can be poured after the bonding agent is cured. In addition, because the bonding agent cannot be pressurized, the bonding effect of the bonding agent and the bar is affected. UTILITY MODEL CONTENT

[0003] To solve the problems in the prior art, the utility model provides a composite material pultruded bar tensile test sample and production mould, which can quickly and efficiently prepare a composite material pultruded bar tensile test sample, and effectively avoid abnormal damage such as clamping and cracking of the bar body during testing.

[0004] To achieve the above purpose, the utility model employs the following technical scheme:

[0005] In the first aspect, a composite material pultruded bar tensile test sample is provided, comprising: a bar body; a reinforcing layer formed by winding a fast-curing fabric prepreg or a fabric impregnated with fast-curing resin on both ends of the bar body and pressurizing and curing.

[0006] Further, the bar body includes a composite material round bar, a threaded bar or an anchor rod.

[0007] Further, the thickness of the reinforcing layer is 2mm-6mm.

[0008] In a second aspect, a mold for manufacturing a composite material pultruded rod tensile test sample is provided, the composite material pultruded rod tensile test sample being the composite material pultruded rod tensile test sample of the first aspect, the mold comprising: an upper mold; a lower mold matched with the upper mold, the upper mold and the lower mold forming a plurality of sets of mold cavities after being closed, each set of the mold cavities comprising a forming cavity for accommodating a reinforcing layer and a remaining cavity for accommodating a rod body.

[0009] Further, a plurality of heating blocks for heating the forming cavities are further included.

[0010] Further, the upper mold and the lower mold are connected by bolts.

[0011] In a third aspect, a method for manufacturing a composite material pultruded rod tensile test sample is provided, the composite material pultruded rod tensile test sample being the composite material pultruded rod tensile test sample of the first aspect, the method comprising: cleaning the areas of the rod body at both ends where the reinforcing layers are to be manufactured; wrapping a layer of glue film on the cleaned rod body at both ends, and then winding a quick-curing fabric prepreg to a set thickness, or wrapping a layer of epoxy structural adhesive on the cleaned rod body at both ends, and then winding a fabric impregnated with quick-curing resin to a set thickness, for forming the reinforcing layers at both ends of the rod body; opening the mold, placing the rod body with the manufactured reinforcing layers into the mold cavities, and then closing the mold; pressurizing and heating the reinforcing layers, so that the reinforcing layers and the rod body are cured and formed into an integrated body to obtain the composite material pultruded rod tensile test sample.

[0012] Further, if the rod body is a round rod, the areas of the rod body at both ends where the reinforcing layers are to be manufactured are polished using 100-800 mesh sandpaper, and then the polished sections of the round rod are cleaned with acetone; if the rod body is a threaded rod or an anchor rod, the areas where the reinforcing layers are to be manufactured need not be polished, and only need to be cleaned.

[0013] Further, after the rod body with the manufactured reinforcing layers is placed into the mold cavities, the upper mold and the lower mold of the mold are closed and fastened by bolts to pressurize the reinforcing layers.

[0014] Further, the reinforcing layers are heated and cured using the heating blocks installed on the mold, and the heating and curing are continued for 1-2 hours.

[0015] Compared with the prior art, the present application has the following beneficial effects: the reinforcing layers are formed at both ends of the rod body by wrapping the quick-curing fabric prepreg or the fabric impregnated with quick-curing resin around the rod body, and the composite material pultruded rod tensile test sample can be quickly and efficiently manufactured, and abnormal damage such as cracking of the rod body can be effectively avoided during the test. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1This is a schematic diagram of the raw materials and molds used to make tensile test specimens of composite material pultruded rods in this embodiment of the present invention; wherein, (a) is the rod body, and (b) is a fast-curing fabric prepreg or a fabric impregnated with fast-curing resin.

[0017] Figure 2 This is a schematic diagram of a composite material pultruded bar tensile test specimen provided in an embodiment of this utility model;

[0018] Figure 3 This is a schematic diagram of the mold used to fabricate tensile test specimens for pultruded composite rods in this embodiment of the present invention. Figure 1 ;

[0019] Figure 4 This is a schematic diagram of the mold used to fabricate tensile test specimens for pultruded composite rods in this embodiment of the present invention. Figure 2 ;

[0020] In the figure: 1. Rod body; 2. Fast-curing prepreg or fabric impregnated with fast-curing resin; 31. Upper mold; 32. Lower mold; 4. Mold cavity; 5. Reinforcing layer; 6. Heating block. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.

[0022] Example 1

[0023] like Figure 1 , Figure 2 As shown, a composite material pultruded bar tensile test specimen includes: a bar body 1; a reinforcing layer 5; the reinforcing layer 5 is formed by winding a fast-curing prepreg or a fabric 2 impregnated with fast-curing resin around both ends of the bar body and then curing it under pressure. The composite material pultruded bars in this invention include plain round bars, threaded reinforcing bars, anchor rods, etc.

[0024] This invention can quickly and efficiently prepare tensile test specimens for composite pultruded rods, and can effectively avoid abnormal damage such as cracking of the specimens during testing.

[0025] In this invention, the length of the reinforcing layer 5 is ≥250mm (the length increases with the diameter and strength of the composite pultruded rod, and the specific length is determined according to the test requirements. The length of the reinforcing layer is generally 0.2 to 0.4 times the total length of the rod body).

[0026] This setup ensures that the testing equipment can effectively clamp the sample during testing, with sufficient contact area between the testing equipment and the sample to increase friction and prevent slippage between the testing equipment and the sample.

[0027] In this invention, the thickness of the reinforcing layer 5 is 2mm to 6mm. This design ensures that the reinforcing layer 5 has a certain thickness and strength, thereby effectively protecting the sample body from being cracked.

[0028] This invention involves wrapping both ends of the rod body with a fast-curing prepreg or a fabric impregnated with fast-curing resin, which greatly shortens the curing time. During tensile testing, the reinforcing layer does not crack within the fixture, thus protecting the rod. The reinforcing layer is cured by mold pressure, which increases the bonding effect between the reinforcing layer resin and the rod.

[0029] Example 2

[0030] Based on the tensile test specimen of composite pultruded rods described in Embodiment 1, this embodiment provides a mold for fabricating tensile test specimens of composite pultruded rods, such as... Figure 3 , Figure 4 As shown, it includes: an upper mold 31; a lower mold 32 that matches the upper mold 31; after the upper mold 31 and the lower mold 32 are closed, they form a number of mold cavities 4. Each mold cavity 4 includes a forming cavity for accommodating the reinforcing layer 5 and a retention cavity for accommodating the bar body 1; it also includes a number of heating blocks 6 for heating the forming cavity. The upper mold 31 and the lower mold 32 are connected by bolts.

[0031] This invention allows for the simultaneous fabrication of 6 or 10 tensile test specimens using a single multi-cavity mold (typically 6 or 10 cavities). This invention improves the tensile test specimen preparation process, enabling rapid and efficient preparation of bar tensile test specimens.

[0032] This invention involves wrapping a fast-curing prepreg or a fabric impregnated with fast-curing resin around both ends of a rod body, placing it in a mold, applying pressure, and then heating and curing it. After the reinforcing layer cures, it is cooled to below 60°C, the mold is opened, and the test sample is removed. During tensile testing, the reinforcing layer of the prepared sample contacts the clamp, preventing the rod from cracking and causing test failure.

[0033] Example 3

[0034] Based on the tensile test specimen of composite pultruded rods described in Example 1 and the mold for making tensile test specimens of composite pultruded rods described in Example 2, this embodiment provides a method for making tensile test specimens of composite pultruded rods, which mainly includes the following steps.

[0035] Clean the areas at both ends of the bar body 1 where reinforcement layers need to be made. Specifically, if the bar body 1 is a smooth round bar, use 60-400 grit sandpaper to sand (without damaging the fibers) both ends of the smooth round bar; then wipe the sanded section of the smooth round bar with acetone. If the bar body 1 is a threaded rib or anchor rod, sanding is not required, only the areas where reinforcement layers need to be made need to be cleaned.

[0036] After cleaning, a layer of adhesive film is wrapped around both ends of the rod body 1, followed by wrapping with fast-curing prepreg fabric to a set thickness. Alternatively, after cleaning, a layer of epoxy structural adhesive is wrapped around both ends of the rod body 1, followed by wrapping with fabric 2 impregnated with fast-curing resin to a set thickness (the thickness of the reinforcing layer is preferably 2mm to 6mm), to form a reinforcing layer 5 at both ends of the rod body 1. If the rod body 1 is a threaded rib or anchor rod, and the reinforcing layer is made by wrapping a layer of epoxy structural adhesive around both ends of the cleaned rod body 1, followed by wrapping with fabric 2 impregnated with fast-curing resin, then the epoxy structural adhesive must fill the threads.

[0037] Open the mold and place the rod body 1 with the reinforcing layer 5 made into the mold cavity 4 (that is, the reinforcing layer 5 is placed in the forming cavity, and the rod body 1 is located in the retention cavity). Then, connect the upper mold 31 and the lower mold 32 of the mold with bolts, close the mold, and tighten it to apply pressure to the reinforcing layer 5.

[0038] After installing the heating block 6, power is applied to heat the reinforcing layer 5 (for 1-2 hours) to solidify the reinforcing layer 5 and the rod body 1 into a single unit. The heating block 6 is then removed, the mold is cooled to below 60°C, and the mold is opened to obtain the composite pultruded rod tensile test specimen. The solidified composite pultruded rod tensile test specimen with the reinforcing layer 5 is then removed from the mold cavity 4.

[0039] This invention allows for the production of one set (typically 6 / 10 rods) or multiple sets (typically 12-36 / 20-60 rods) at a time, improving the efficiency of test sample production. The reinforcing layers at both ends of the rods are made of fast-curing prepreg or fabric impregnated with fast-curing resin and are cured by heat, shortening the curing time of the reinforcing layers and further improving the efficiency of test sample production. The reinforcing layers are cured by mold pressure, increasing the adhesion between the reinforcing layer resin and the rods.

[0040] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.

Claims

1. A tensile test specimen for pultruded composite rods, characterized in that, include: Bar body (1); The reinforcing layers (5) are formed at both ends of the rod body (1) by wrapping the fabric (2) with a fast-curing prepreg or a fabric impregnated with a fast-curing resin around the two ends of the rod body (1) and then curing it under pressure.

2. The composite pultruded bar tensile test specimen according to claim 1, characterized in that, The bar body (1) includes composite material round bars, threaded bars, or anchor rods.

3. The composite pultruded bar tensile test specimen according to claim 1, characterized in that, The thickness of the reinforcing layer is 2mm to 6mm.

4. A mold for fabricating tensile test specimens of composite pultruded bars, characterized in that, The tensile test specimen for the composite pultruded bar is the tensile test specimen for the composite pultruded bar as described in any one of claims 1 to 3, and the mold includes: Upper mold(31); The lower mold (32) is matched with the upper mold (31). After the upper mold (31) and the lower mold (32) are closed, a number of mold cavities (4) are formed. Each set of mold cavities (4) includes a forming cavity for accommodating the reinforcing layer (5) and a retention cavity for accommodating the rod body (1).

5. The mold for fabricating tensile test specimens of composite pultruded bars according to claim 4, characterized in that, It also includes several heating blocks (6) for heating the molding cavity.

6. The mold for fabricating tensile test specimens of composite pultruded bars according to claim 4, characterized in that, The upper mold (31) and the lower mold (32) are connected by bolts.

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