What Is Tensile Stress?

When an object is deformed due to external factors (force, humidity, temperature field changes, etc.), an internal force interacting between various parts of the object is generated to resist this external factor and try to restore the object from its deformed position to Position before deformation. The stress is divided into normal stress perpendicular to the same section and shear stress tangent to the same section.

When an object is deformed by external factors (force, humidity, temperature field changes, etc.),

Strain is also called "relative deformation". A physical quantity that causes a relative change in the geometry and size of an object due to external factors (load, temperature change, etc.). Deformation (elongation or contraction) within the unit length of an object's line segment, that is, the ratio of the change in the length of the line segment to the original length of the line segment is called "normal strain" or "line strain", and is represented by the symbol ; Change called "

Difference between tensile stress and compressive stress

A cylinder is compressed at both ends, so the stress along its axis is

The type used in the static load tensile test is generally a smooth round sample, and the working length of the sample (standard length)

Strain gauges or strain gauges are instruments used to measure objects due to internal stress. Generally, the signal of the strain gauge is collected and converted into an electrical signal for analysis and measurement.

The method is: affix the strain gauge to the object to be measured and contracted together with the strain of the object to be measured, so that the metal foil inside will expand or contract with the strain. Many metals change their electrical resistance when they are mechanically elongated or shortened. Strain gauges use this principle to measure strain by measuring changes in resistance. Copper-chromium alloy is used as the sensitive grid of the strain gauge, and its resistance change rate is constant, which should be proportional to the value.

Through a Wheatstone bridge, this proportional relationship of resistance can be converted into a voltage. Different instruments can then convert this voltage change into measurable data.

For stress gauges or strain gauges, the key indicators are: test accuracy, sampling speed, number of channels that the test can support, dynamic range, supported strain gauge models, etc. In addition, the software supporting the stress meter is also very important. It needs to be capable of real-time display, real-time analysis, real-time recording and other functions. The high-end software also has various signal processing capabilities.

In addition, some instruments are designed based on the principles of spectroscopy and diaphragms.