3 results about "Static strength" patented technology

The invention provides a strength and fatigue analysis method and equipment for a welded integrated planet carrier, belongs to the technical field of welding processes and weld strength and fatigue evaluation, and establishes a temperature / phase dependent material performance parameter library, and adopts Johnson-Mehl-Avrami and Koidinen-Marburst formulas to process phase change kinetics. And a welding process simulation system is constructed through single-claw model simplification, grid gradient control and a 3D Gaussian heat source model. Data transmission and rebalance verification are achieved, and it is ensured that the displacement error is smaller than or equal to 0.85%. And supplementing a complete model and setting boundary conditions, introducing 50% residual stress relaxation correction, dividing the welding seam / heat influence area into 10 groups according to the yield strength difference, and calculating the fatigue life by adopting a Basquin formula. According to the method, through multi-physics field coupling and sub-model subdivision, accurate evaluation of the static strength and the fatigue life of the welding structure is achieved, and the application reliability is improved.

This invention belongs to the field of flexible body aircraft technology, specifically disclosing a method for measuring the stiffness of a flexible wing. This method is based on a static strength and stiffness measurement platform for flexible wings, which includes a test bench support frame, a specimen fixing platform, support rods, tension ropes, a rangefinder, and a counterweight loading component. The stiffness measurement method includes: calculating the test load; installing the flexible wing test specimen; marking the flexible wing test specimen; designing and preparing the counterweight loading component; applying equivalent loading under the test condition; measuring the bending and torsional stiffness boundaries; and post-processing the measurement results. This measurement method significantly improves loading accuracy and can simulate loads under bending, torsion, or combined bending and torsion conditions of flexible wings to obtain stiffness and instability boundaries. It overcomes the shortcomings of traditional flexible wing structural stiffness measurement methods, which can only perform rough loading and cannot handle heavy loads, and can measure the load-bearing capacity and stiffness of high aspect ratio, high load-bearing special-purpose flexible wings.

This invention discloses a method for evaluating the static strength of welded structures, comprising: establishing a finite element model of the welded structure and performing finite element static strength calculations using a coarse mesh to locate weld hotspots; refining the mesh at the weld hotspot locations and calculating the total weld stress through internal stress linearization; determining material parameters, including yield strength, tensile strength, elongation at break, Young's modulus, tangent modulus, and total critical strain; determining the section modulus based on the material parameters; determining the welding coefficient based on weld type, weld quality, and stress type; calculating the weld strength based on the section modulus, welding coefficient, and material parameters; determining a safety factor based on the material parameters and an assessment of the consequences of weld failure; and obtaining the evaluation result by comparing the ratio of the weld strength to the safety factor with the total weld stress. This invention can more realistically reflect the stress state at the weld location and improve the accuracy of the evaluation by refining the design parameters.