2 results about "Concentration factor" patented technology

This invention belongs to the field of aircraft structural performance evaluation technology, specifically involving a method for determining the allowable stress for durability design of aircraft metal structures. First, the baseline local allowable stress is calculated under a given material and load spectrum using fatigue analysis. Considering actual structural factors, an equivalent stress concentration factor is introduced to correct the baseline local allowable stress. Furthermore, a stress correction factor is introduced based on the correction of theoretical analysis results using fatigue tests. Considering reliability requirements, a fatigue uncertainty factor is also introduced, thereby establishing a set of analogous calculation formulas to determine the allowable stress for durability design. The calculation formula is: where, [σ max,0 [K] is the reference local allowable stress. te C is the equivalent stress concentration factor, SCF is the stress correction factor, FSF is the fatigue uncertainty factor, and C is the stress concentration factor. load This is the load conversion factor. This invention simplifies the fatigue test matrix while ensuring the accuracy of theoretical analysis; it can quickly determine whether the structural fatigue margin meets the requirements, thus enabling durability analysis to cover the entire load-bearing structure of the aircraft.

Provided is a concentration device for concentrating a test body fluid, capable of obtaining a test body fluid concentrate at a desired concentration factor, a test body fluid concentration method using the concentration device, a test body fluid inspection method using the test body fluid concentration method, and a test kit provided with the concentration device. A concentration device for concentrating a test body fluid that is an aqueous solution containing a high molecule, includes a cylinder that contains a particulate superabsorbent polymer and a piston that can be inserted into the cylinder, the cylinder has a liquid holding portion for holding a portion of the test body fluid injected into the cylinder at a bottom portion, the superabsorbent polymer is contained in the cylinder in contact with the liquid holding portion above the liquid holding portion, and the piston has a front end portion having a smaller pore size than the particle size of the superabsorbent polymer after water absorption.