Strength Test
Material strength test Determination of material yield limit, intensity limit or fatigue limit. The structural strength test determines the ultimate endurance of the structure, but it is not only related to the strength of the material, but also the geometric shape, the mechanism fitting, and external force action form, according to the experimental loading method is the static strength test, the dynamic strength test and fatigue strength test. According to the ambient temperature, it can be divided into normal temperature strength test, heat (high temperature) intensity test or cold (low temperature) intensity test. Test equipment includes static strength test equipment, dynamic intensity test equipment and fatigue strength test equipment.
Heat intensity test
Structure test is one of the ability to observe and study the mechanical state and resistance of the aircraft structure or component in the thermal environment. Thermally intensity test requires an environment that is equivalent to the actual flight process equivalent to the actual flight.
Introduction
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The content of the structure test is to observe and study the mechanical nature and resistance of the aircraft structure or components in the hot environment. ability. Thermally intensity test requires an environment that is equivalent to the actual flight process equivalent to the actual flight. In addition to static, dynamic, fatigue tests in the hot environment, there are also heat transfer tests, heat-resistant insulation tests, and creep test, etc. The heating is divided into two types of flow and non-fluidity. The flow heating is represented by a high temperature structure. The construction and test cost of such equipment is high, the test piece is limited, and the heating duration is short, but the simulation effect is relatively realistic. The most widely used quartz tube lamp infrared radiation heating system controlled by electronic computer. At the actual flight heating, the size and temperature of the load and the distribution of the load change over time. In order to simulate this process, the structure surface is divided into several regions, and the unit area heating rate and load value of each region are different, and the program heating and loading should be coordinated.
In the test system, the computer is collected and processed in real time in real time to acquire and process measurement data in real time in addition to heating and loading of each region. The cathode ray tube screen connected to the computer can display changes in key data in real time for monitoring. Once an abnormal occurs, the computer automatically issues an alert and take emergency measures (also manually intervening). Common measuring sensors are thermocouples (or thermistors), radiant heat flow gauges, high temperature resistance strain chips, high temperature displacement, measurement gauges. The heater is usually used in quartz tubular iodine tungsten lamps, typically the unit area heating rate can reach 1135 kilowatts / m 2. In order to achieve higher heating rate, such as 4000 kilowatts / m 2, a specially treated graphite heater can be used. It is still difficult to produce extremely high temperature in thermal intensity test, and high temperature strain measurement technology is still a big problem. Non-contact measurement techniques such as optical fibers and lasers are increasingly attached.
Shear strength test
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Chinese name
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shear strength test
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English name
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shear strength test
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Following technical procedures, measure the technical operation of the soil resistance shear failure. The method commonly used in the laboratory has a direct shear test, a three-axis compression test, and a non-side compressive strength test.
Definition
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application discipline
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Water Conservancy Technology (first-class discipline), rock mechanics, soil mechanics , Geotechnical Engineering (Secondary Discipline), Soil (Water Conservancy) (Level 3 Discipline)