Evaluation Service

Evaluation Service

The evaluation service consists of evaluation platforms for high-performance fibers, fiber preforms and resin matrix composites, equipped with laboratories dedicated for mechanical properties, thermal properties, physical properties, environmental aging performance, chemical analysis, sample preparation and nondestructive tests respectively. The operation range covers evaluations on mechanical properties, thermal properties, dynamic fatigue behavior, environmental aging performance, chemical properties and nondestructive testing, etc. It is committed to help composites-related enterprises to establish and improve evaluation systems, reduce research and development costs, save a large amount of inspection and testing expenses, and improve the competitiveness of products in the international market.

Test name Description Test item Applied standard
Nondestructive testing

Nondestructive testing (NDT) is a method to inspect and test the inside and surface structure, nature and state of specimens by physical or chemical means and with the help of techniques and apparatus without damaging the specimens. The evaluation team provides non- destructive testing service and technical support to customers by virtue of its talent advantage, technique advantage and service consciousness. At present, the evaluation team focuses on the composites used for aero-engines and owns several sets of nondestructive testing equipment.

1.Ultrasonic A-scan nondestructive testing
2.Ultrasonic measurement of thickness
3.Ultrasonic phased-array nondestructive testing
4.Ultrasonic C-scan nondestructive testing
5.240kV nanofocus CT nondestructive testing
6.X-ray digital detection
7.Nondestructive testing by laser shearography
8.Nondestructive testing by infrared thermal imaging
9.Acoustic emission testing
10.DIC strain measurement

GB/T 23908
GB/T 11344
GB/T 32563-2016
GB/T 38537-2020
GB/T 38535-2020
GB/T 35388-2017
GB/T 34886-2017
GB/T 38883-2020
GB/T 26644-2011
EN ISO 9513

Strength failure analysis

At present, the evaluation team has rich experience in testing mechanical properties and a complete equipment system, which can conduct the testing and evaluation on the mechanical properties of composites under tensile, compressive, shearing, bending, impact and other loads. By means of the collection of acoustic signals in the testing process, the CT scanning of damage morphology of different test sections, the real-time observation and record of stress and strain, and the fracture analysis for final rupture, the main failure criteria of composite parts under given loads are determined, the damage mechanism causing material failure is analyzed and the damage variables are defined so that the damage and failure of composites can be quantitatively evaluated.

1.Tensile mechanical properties test
2.Compressive mechanical properties test
3.Shearing mechanical properties test
4.Flexural mechanical properties test
5.Fracture toughness test
6.Impact performance test

ASTM D3039
ASTM D6641
ASTM D7808
ASTM D2344
ASTM D5528
GB/T 1451

Fatigue and damage tolerance

Fatigue test is usually an extension of static test,by which the S-N curve of composite parts under symmetrical loads ( stress ratio R=-1 ) is plotted. With a typical stress ratio, the fatigue test is carried out to obtain a constant life fatigue diagram, usually a Goodman diagram. Such a test procedure can cover the life prediction and evaluation of composite parts. In the case of multi-load spectrum superposition, the fatigue damage accumulation theory ( Miner theory ) is used for linear superposition. The parameters of damage tolerance to be evaluated are residual life, residual strength and residual stiffness.

Tensile-tensile fatigue test
Bearing fatigue test of laminates
Delamination growth fatigue test
Fatigue test of sandwich core materials

ASTM D3479
ASTM D 6873
ASTM D6115
ASTM C 394

Numerical simulation technology

Due to the designability of composite materials, the selection of component materials and the change of preform structure will significantly affect the material properties. By means of simulation technology and commercial softwares such as Abaqus, Ansys and MSC.Patran/Nastran, a finite element model can be established, which, with material parameters input, can make simulation calculation of static mechanical properties ( modulus and strength ) of composites to provide effective support for structural design and save test cost and time. Meanwhile, for dynamic impact and fatigue behavior, it can conduct complete simulation of dynamic behavior and evaluation on damage tolerance with the help of corresponding modules and auxiliary programming methods.