Composite materials and others

2022.03.10  

Basic mechanical properties of composite materials

Tensile property

  Tensile properties include tensile strength, elastic modulus, Poisson ratio and so on。For products such as high-pressure vessels, high-pressure tubes, blades, etc., the tensile properties of polymer composites must be measured before product design and inspection can be carried out。

 

Bending property

  The test specimen for bending properties is generally a long strip of rectangular cross-sectional area, referred to as a rectangular beam。The national standard has certain requirements for the span (span or offset) height (sample thickness) ratio (L/h) of the sample, generally requiring L/h≥16, and for unidirectional fiber reinforced materials, requiring L/h≥32。

 

◆ Compression performance

  The compression properties of polymer composites are closely related to the variety, properties, molding process and interface of the two polymers, and the compression properties of the same composite materials vary greatly。

 

◆ Shear performance

  Due to the layered structure characteristics of polymer composite materials, there are three shear properties in different parts of the product in use under different stress conditions, namely in-plane shear, interlayer shear and broken grain shear。

 

◆ Impact performance

  When the product is subjected to dynamic load, the impact strength (toughness) performance index of the material is required, and the impact strength level also indicates the toughness of the material, which is one of the performance indicators of the material selection。

 

◆ Directivity of performance

  The mechanical properties of fiber reinforced composites have obvious directivity。Tensile strength/modulus, bending strength/modulus, compressive strength/modulus is the maximum along the fiber direction, and the minimum along the fiber direction is 45°。The in-plane shear strength/modulus and Poisson's ratio, contrary to the above situation, are maximum in the direction of 45°。

 

Physical and chemical properties of composites

◆ Load heat deformation temperature

  This property directly reflects the heat resistance of the polymer (resin), and the load heat deformation temperature of different polymer composites is very different。


Special properties of composite materials

◆ Persistent creep

  The polymer composite material has creep at room temperature. When it is subjected to tensile, the creep becomes smaller, and when it is subjected to bending and shearing, the creep becomes larger。The lasting strength is generally 40%-50% of the damage strength。

 

◆ Fatigue performance

  The fatigue properties of polymer composites are closely related to stress state, resin variety, fiber direction, molding process and cycle times。If the cycle to 5×106, the fatigue strength is about 25%-30% of the static strength。

 

◆ High and low temperature performance

  The performance of polymer composites depends on the type of polymer, and there are currently high temperature resistant polymers that can withstand more than 350 ° C。At low temperatures, its performance is improved, the lower the temperature, the higher the strength, including impact toughness is also the same, generally increased by 20%-30%。


Composite material mechanical properties test solution 

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Microcomputer control electronic universal testing machine

     Microcomputer control electronic universal testing machineIt is mainly used for tensile, bending, compression, shear, crack propagation and other mechanical properties of composite materials。With three closed-loop control methods of stress, strain and displacement, the maximum load, tensile strength, bending strength, compressive strength, shear strength, elastic modulus, elongation at break, Poisson ratio and other parameters can be calculated。Test and provide data according to national standards and ISO, JIS, ASTM, DIN and other international standards。

  • The main machine is a floor door structure, and the middle beam is guided by a high-precision guide bar, which has high rigidity and good linear motion characteristics.

  • The equipment is equipped with high and low temperature environment box, full temperature stretching fixture, video extension meter, which can complete the full-field strain test under high and low temperature environment of -70-350℃;

  • The coaxiality adjustment device can provide good coaxiality accurately and effectively;

  • Adopting circular arc silent synchronous belt and imported AC servo motor, with well-designed transmission mechanism, high efficiency and low noise;

  • Automatic switching control mode: In the case of stress rate control, it can be automatically switched to the displacement rate control mode according to the test requirements of the material;

  • With overload, overcurrent, overvoltage, limit and other safety protection modes;

  • With calibration and linear correction function, load and displacement can be automatically calibrated。

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     Full temperature hydraulic jig

       Full temperature wedge hydraulic fixture for high and low temperature box special fixture, simple operation, clamping stable and reliable, can be used in (-70 ~ 350℃) high and low temperature box。During the test, the jig cylinder is placed outside the high and low temperature box and cooled by air cooling, while the clamp is placed inside the high and low temperature box to directly clamp the sample。During the test, the wedge-shaped surface design can automatically compensate the change of specimen thickness, which is convenient for specimen clamping and centering, and the clamping force will increase correspondingly with the increase of the test load。The main parts of the fixture are made of alloy steel, the surface is plated with hard chromium and polished, which has high strength and strong anti-corrosion and anti-rust ability。The tensile properties of conventional composite materials and plastics can also be tested。


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Electro-hydraulic servo fatigue testing machine

       2024欧洲杯买球Electro-hydraulic servo fatigue testing machineIt is a high-precision and multi-purpose testing machine for fatigue performance testing of various metal materials, non-metal materials, composite materials, polymer materials, structural parts, etc。With different fixtures, mechanical tests such as pulling, pressing and pressing can be carried out。Additional environmental test equipment can be configured to complete environmental simulation tests under high temperature, low temperature, salt spray and corrosion。

       All Chinese Windows platform test software, can carry out sine wave, triangular wave, trapezoid wave, custom wave and other fatigue curve test。Real-time dynamic display Real-time display force-time curve, displacement-time curve, deformation (need to be equipped with extensometer) -time and other test curves。The data can be processed and analyzed, the test results can be automatically saved, the test curve can be re-pulled after the test, and the curve can be analyzed, for example, the test process can be reproduced by the curve, or the curve can be compared and enlarged。

Meet the criteria:

◆ JJG 556 "Axial Extension Fatigue Testing Machine"

◆ JB/T 9397 "Tensile fatigue testing machine technical conditions"

◆ GB/T 3075 "Metal Material fatigue test axial force control method"

◆ GB/T 26077 "Metal Material fatigue test axial strain control method"

◆ GB/T 2611 "General Technical Requirements for Testing Machine"

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Special instrumental drop weight impact testing machine for composite materials

      The special instrument drop hammer impact testing machine for composite materials is mainly suitable for prefabrication damage testing of composite plates, which meets various aerospace specifications。Impact value sensor and velocity sensor are adopted,The load and deformation transient values of the sample were measured by the high-speed data acquisition system,Shock absorption work,The force-displacement-energy curve of the impact process and the characteristic points on the curve: slope discontinuity force F1,Maximum contact force Fm,Maximum power Wm,Total impact energy Wt and corresponding displacement,The deformation analysis of sample during impact is realized,It reflects the ability of the material to resist the dynamic impact load, the stress and deformation characteristics of the sample under the impact load。


Fracture toughness test

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Tensile test

Compression test

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Shear test

Bending test

Honeycomb test

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Home appliance parts

Home appliance parts include evaporator, radiator, condenser, heat exchanger, cooling water pipe, copper pipe, aluminum pipe, washing machine water pipe, bathroom PVC pipe and so on。

The testing machine can provide a series of test solutions for the blasting strength performance, compressive strength performance, airtight performance, pulse fatigue performance, vibration fatigue performance, and cold and thermal shock performance of household appliance parts。

Wanyi can provide heat exchanger pressure burst testing machine, pulse fatigue testing machine, air tightness leak testing machine, vacuum testing machine, endurance cycle testing machine, cold and thermal impact testing machine, internal corrosion testing machine, tensile testing machine, pendulum impact testing machine, fatigue testing machine and other test equipment,Meet customer needs,Welcome to consult。

 

Cartons, packaging containers

Carton, packaging container is mainly compression test, Wanji can provide electronic universal testing machine, microcomputer control packaging container pressure testing machine。

 

瓷砖

Ceramic tile is mainly anti-bending test, Wanji can provide microcomputer control ceramic tile anti-bending testing machine。

 

textile

Textile is mainly tear strength test, Wanji can provide electronic universal testing machine。


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