CN101787110B - Photoelastic plastic material and preparation method - Google Patents

Abstract

The invention relates to a photoelastic plastic material and a preparation method, belonging to the field of materials. The mass ratio of the following raw materials is included: epoxy resin:maleic anhydride:dibutyl phthalate=80-100:24-60:32-80. The present invention can be used for simulating under the small elasto-plastic deformation, the force state analysis of some complex components, such as the residual stress research in the straightening process of the research components (such as rails, steel plates), etc., the photoelastoplastic method shows great It is not only effective and convenient, but also the most economical method. The defect of the original photoelastic technology is only limited to the research of stress and strain in the loading process, and cannot study the state of stress and strain after unloading. Use the photoelastic plastic material of the present invention to load and obtain isochromatic lines on a digital photoelastic instrument and then unload it, observe the change of the number of stripes in the photoelastic plastic material after unloading, the material can make the residual stress of the research component change with time and keep it for 15 minutes .

Description

Photoelastic plastic material and preparation method

technical field

The invention relates to a photoelastic plastic material and a preparation method thereof, and is characterized in that it relates to a photoelastic plastic material with component residual stress under the condition of small elastic plastic deformation, and belongs to the field of materials.

Background technique

Obtaining various mechanical quantities of structures by photoelasticity is a basic problem in engineering technology. Although a series of theoretical analysis methods have been established in engineering mechanics, structures and geometric shapes required in many high-tech fields It is particularly complex, and the load conditions and working environments (high temperature, high pressure, underground, liquid, strong magnetic field, strong radiation, dynamics, etc.) are becoming more and more diverse, making theoretical analysis very difficult; therefore, it is particularly important to use experimental methods. Even the only means. This method is suitable for elastic deformation conditions, and the stress-strain state disappears immediately after the member is unloaded.

The photoplastic method is based on the classic concept of photoelasticity. It uses suitable polymer materials to make models for experiments to determine the elastic-plastic stress and strain state of the prototype structure. According to the different research objects and deformation degrees, photoplastic It is mainly a photoplastic method to study the residual strain state of the structure after unloading under large plastic deformation.

Due to the limitations of the photoelastic method and the fact that there are a large number of elastic-plastic and large plastic deformation problems in engineering, the photoplastic method, which has the advantages of intuition, convenience, and economy, has received great attention in recent years and has achieved rapid development. .

Contents of the invention

The object of the present invention is to provide a photoelastoplastic material that can be used to study the residual stress of components under the condition of small elastic-plastic deformation, and still retain the state of stress and strain after unloading, and its preparation method.

Technical solution: the present invention comprises the mass ratio of following raw materials: epoxy resin: maleic anhydride: dibutyl phthalate=80-100: 24-60: 32-80;

The preparation method is as follows: (1) Pour the above-mentioned epoxy resin into a beaker, and then put the beaker into a water bath at 100°C-120°C and boil for 40-60 minutes while stirring continuously to volatilize impurities and precipitate slag;

(2) Cool the water temperature in the water bath to 50-60°C, add a maleic anhydride curing agent to the epoxy resin after the water bath, and stir evenly in one direction for 20-30 minutes to make a uniform mixed solution A;

(3) Take the above-mentioned dibutyl phthalate plasticizer and pour it into a beaker, heat it in a water bath on an electric stove until the curing agent is completely melted, and control the temperature at 80°C-95°C to make solution B;

(4) Solution A of step (2) is mixed with solution B of step (3) to make C solution, and N-N-dimethylaniline catalyst is added in C solution, and the addition amount of catalyst is C solution gross weight 0.5-1.0%, when adding, stir evenly in one direction while pouring, the temperature is controlled between 50-60°C, after stirring for 20-30 minutes, make D solution, pour D solution into the mold, put it into the constant temperature at 40- In an oven at 65°C, let it stand for 40-60 minutes, and cast when there are no bubbles;

(5) After the casting is completed, put the mold into a drying oven at a constant temperature of 42-44°C for the first curing treatment. The curing time is 48-72 hours. After the model is completely gelled, the mold is demoulded, and then the second 120 The curing treatment at ℃, the curing time is 10-15 hours, and the finished material is obtained.

(6) Machine the finished material, observe whether there is initial stress on the photoelasticometer, and if there is initial stress, annealing treatment is required.

The present invention includes the mass ratio of the following raw materials: epoxy resin:maleic anhydride:dibutyl phthalate=100:30-50:40-70.

The present invention includes the mass ratio of the following raw materials: epoxy resin: maleic anhydride: dibutyl phthalate = 80: 24-48: 32-64.

Epoxy resin is a low molecular weight polymer of bisphenol A and epichlorohydrin.

The present invention is based on the two methods of photoelasticity and photoplasticity. It is mainly used to study the photoelasticity and plasticity of the structure that still retains the state of stress and strain after unloading under small elastic-plastic deformation. By changing the ratio of photoelastic materials , prepared photoelastoplastic stress materials. The experimental results show that the photoelastic-plastic method can be used to simulate the force state analysis of some complex components under small elastic-plastic deformation, such as the research on the residual stress in the straightening process of components (such as rails and steel plates). The plastic method shows great advantages, not only effective, convenient, but also the most economical method. The defect of the original photoelastic technology is limited to the research of stress and strain in the loading process, and cannot study the state of stress and strain after unloading. The photoelastic plastic material of the present invention is loaded on a digital photoelastic instrument to obtain isochromatic lines and then unloaded to observe the change of the number of stripes in the photoelastic plastic material after unloading. This material can make the residual stress of the research component change with time and retain at least 15 minute.

Description of drawings

Fig. 1 the present invention is the isochromatic line fringe figure of photoelastoplastic material disc under different stress conditions;

Fig. 2 is the contour fringe diagram of the photoelastoplastic material disc of the present invention under different stress conditions;

Fig. 3 is an isochromatic line diagram every minute after photoelastoplastic material of the present invention is unloaded;

Fig. 4 is the curing figure of the present invention;

Fig. 5 is an annealing curve diagram of the present invention.

Detailed ways

Example 1

The present invention comprises the mass ratio of following raw material: epoxy resin: maleic anhydride: dibutyl phthalate=100: 30: 40; Epoxy resin is the low molecular weight polymer of bisphenol A and epoxy chloropropene .

The preparation method is as follows: (1) Pour the above-mentioned 100 grams of epoxy resin into a beaker, then put the beaker into a water bath at 100°C and boil for 50 minutes, and keep stirring to volatilize impurities and precipitate slag;

(2) Cool the water temperature in the water bath to 55°C, add 30 grams of maleic anhydride curing agent to the epoxy resin after the water bath, and stir evenly in one direction for 20-minutes to make a uniform mixed solution A;

(3) Take the above-mentioned 40 grams of dibutyl phthalate plasticizer and pour it into a beaker, heat it in a water bath on an electric stove until the plasticizer is completely melted, and the temperature is controlled at 85° C. to make solution B;

(4) Mix solution A of step (2) with solution B of step (3) to make solution C, add 0.2 gram of N-N-dimethylaniline catalyst in solution C, stir evenly in one direction while pouring, The temperature is controlled at 52°C, and after stirring for 20 minutes, the D solution is made, and the D solution is poured into the mold, placed in an oven with a constant temperature of 42°C, and left for 40 minutes. When there are no bubbles, cast;

(5) After the casting is completed, put the mold into a drying oven at a constant temperature of 42°C for the first curing treatment. The curing time is 50 hours. After the model is completely gelled, the mold is demoulded, and then the second curing treatment at 120°C is performed. , the curing time is 12 hours, and the finished material is obtained.

(6) Machine the finished material, observe whether there is initial stress on the photoelasticometer, and if there is initial stress, annealing treatment is required.

The photoelastic plastic material is loaded on the digital photoelastic instrument to obtain the isochromatic line and then unloaded, and the change of the number of stripes in the photoelastic plastic material after unloading is observed. This material can make the residual stress of the research component change with time and keep it for 15 minutes.

Example 2

The present invention comprises following raw material epoxy resin: maleic anhydride: dibutyl phthalate, and the mass ratio of raw material is epoxy resin: maleic anhydride: dibutyl phthalate=90:50: 60; wherein: the epoxy resin is a low molecular weight polymer of bisphenol A and epichlorohydrin.

The preparation method is as follows: (1) Pour the above-mentioned 90 grams of epoxy resin into a beaker, then put the beaker into a water bath at 100°C and boil for 50 minutes, and keep stirring to volatilize impurities and precipitate slag;

(2) Cool the water temperature in the water bath to 55°C, add 50 grams of maleic anhydride curing agent to the epoxy resin after the water bath, and stir evenly in one direction for 20 minutes to make a uniform mixed solution A;

(3) Take the above-mentioned 60 grams of dibutyl phthalate plasticizer and pour it into a beaker, heat it in a water bath on an electric stove until the plasticizer is completely melted, and the temperature is controlled at 75° C. to make solution B;

(4) Mix solution A of step (2) with solution B of step (3) to make solution C, add 0.1 gram of N-N-dimethylaniline catalyst in solution C, stir evenly in one direction while pouring, The temperature is controlled at 52°C, and after stirring for 20 minutes, the D solution is made, and the D solution is poured into the mold, placed in an oven with a constant temperature of 42°C, and left for 40 minutes. When there are no bubbles, cast;

(5) After the casting is completed, put the mold into a drying oven at a constant temperature of 42°C for the first curing treatment. The curing time is 50 hours. After the model is completely gelled, the mold is demoulded, and then the second curing treatment at 120°C is performed. , the curing time is 12 hours, and the finished material is obtained.

(6) Machine the finished material, observe whether there is initial stress on the photoelasticometer, and if there is initial stress, annealing treatment is required.

The photoelastic plastic material is loaded on the digital photoelastic instrument to obtain the isochromatic line and then unloaded, and the change of the number of stripes in the photoelastic plastic material after unloading is observed. This material can make the residual stress of the research component change with time and keep it for 15 minutes.

Example 3

The present invention comprises following raw material mass ratio: epoxy resin: maleic anhydride: dibutyl phthalate=80: 40: 50; Wherein: epoxy resin is the low molecular weight polymerization of bisphenol A and epoxy chloropropene thing.

The preparation method is as follows: (1) Pour the above-mentioned 80 grams of epoxy resin into a beaker, then put the beaker into a water bath at 100° C. and boil for 50 minutes while stirring continuously to volatilize impurities and precipitate slag;

(2) Cool the water temperature in the water bath to 55°C, add 40 grams of maleic anhydride curing agent to the epoxy resin after the water bath, and stir evenly in one direction for 20 minutes to make a uniform mixed solution A;

(3) Take the above-mentioned 50 grams of dibutyl phthalate plasticizer and pour it into a beaker, heat it in a water bath on an electric stove until the plasticizer is completely melted, and the temperature is controlled at 75° C. to make solution B;

(4) Mix solution A of step (2) with solution B of step (3) to make solution C, add 0.1 gram of N-N-dimethylaniline catalyst in solution C, stir evenly in one direction while pouring, The temperature is controlled at 52°C, and after stirring for 20 minutes, the D solution is made, and the D solution is poured into the mold, placed in an oven with a constant temperature of 40°C, and left for 40 minutes. When there are no bubbles, cast;

(5) After the casting is completed, put the mold into a drying oven at a constant temperature of 42°C for the first curing treatment. The curing time is 55 hours. After the model is completely gelled, the mold is demoulded, and then the second curing treatment at 110°C is performed. , the curing time is 15 hours, and the finished material is obtained.

(6) Machine the finished material, observe whether there is initial stress on the photoelasticometer, and if there is initial stress, annealing treatment is required.

Claims (3)

1. the preparation method of photoelastic plastic material, it is characterized in that: the mass ratio that comprises following raw materials according: Resins, epoxy: MALEIC ANHYDRIDE: dibutyl phthalate=80-100: 24-60: 32-80, Resins, epoxy are the low-molecular weight polymer of dihydroxyphenyl propane and epoxy chloropropionate alkene;

The preparation method is as follows: (1) is poured above-mentioned Resins, epoxy in the beaker into, puts in 100 ℃ the water-bath together with beaker then and boils 40-60 minute, and constantly stir, with volatilization impurity and precipitation bits;

(2) water temperature in the water-bath is cooled to 50～60 ℃, add the maleic acid anhydride curing agents in the Resins, epoxy after water-bath, and evenly stirred 20-30 minute, make homogeneous mixture solotion A along a direction;

(3) get above-mentioned dibutyl phthalate softening agent and pour beaker into, heating in water bath to solidifying agent melts fully on Electric stove, and temperature is controlled at 80 ℃-95 ℃, makes solution B;

(4) solution A of step (2) is mixed with the solution B of step (3), make C solution, in C solution, add N, the accelerine catalyzer, the add-on of catalyzer is the 0.5-1.0% of C total solution weight, adds fashionable limit bevelling and evenly stirs along a direction, temperature is controlled between 50～60 ℃, stir after 20-30 minute, make D solution, pour D solution into mould, put into constant temperature at 40-65 ℃ baking oven, quiet putting 40-60 minute when waiting not have bubble, cast;

(5) after casting is finished, mould put into constant temperature carries out the solidification treatment first time at 42～44 ℃ in the drying baker, 48-72 hour set time, treat the demoulding behind the model complete gelation, carry out 120 ℃ solidification treatment for the second time again, 10-15 hour set time, obtain finished-product material.

(6) finished-product material is carried out machining, on photo-elastic instrument, observe whether initial stress is arranged, if there is initial stress will carry out anneal.

2. the preparation method of photoelastic plastic material according to claim 1 is characterized in that: the mass ratio that comprises following raw materials according: Resins, epoxy: MALEIC ANHYDRIDE: dibutyl phthalate=100: 30-50: 40-70.

3. the preparation method of photoelastic plastic material according to claim 1 is characterized in that: the mass ratio that comprises following raw materials according: Resins, epoxy: MALEIC ANHYDRIDE: dibutyl phthalate=80: 24-48: 32-64.

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