Method for forecasting ultimate bearing capacity of transmission shell under impact actoin of engine

Abstract

The invention discloses a method for forecasting the ultimate bearing capacity of a transmission shell under the impact action of an engine, which fully utilizes the advantages of short linear elasticfinite element analysis and calculation period, accurate static safety coefficient prediction structure fracture position and the like to quickly determine a plurality of strength weak positions of the transmission shell. Through elastic-plastic finite element analysis, plastic strain of multiple strength weak positions of the transmission shell is calculated, the minimum torque in the multiple strength weak positions when the plastic strain is equal to the elongation of a material serves as a transmission shell fracture criterion, and the ultimate bearing capacity of the transmission shell is forecasted; due to the fact that the material elongation is plastic strain during structural fracture and has strong correspondence with structural fracture, the limit bearing capacity of the transmission shell is evaluated more accurately and more precisely by adopting the material elongation.

Description

technical field [0001] The invention relates to a method for predicting the ultimate bearing capacity of a transmission housing, in particular to a method for predicting the ultimate bearing capacity of a transmission housing under the impact of an engine. Background technique [0002] The ultimate bearing capacity of the transmission housing is the maximum load capacity that the transmission housing can bear when it breaks and fails. As an important basic component, the transmission housing should have sufficient strength to resist the loads such as the gear meshing force caused by the strong torque of the engine and the inertia force of the transmission caused by uneven road surfaces, so as to support the gear shaft and protect the gear transmission mechanism, so as to meet the needs of the entire vehicle for the transmission. Different torque and speed requirements. [0003] In the process of product design, two technical means are usually used to obtain the ultimate bea...

AI Technical Summary

Problems solved by technology

The application of simulation technology to obtain the ultimate bearing torque of the transmission case is fast and can be predicted in the early stage of product development, but the following problems exist in the current simulation technology; ① There are many forms of stress, such as Mises stress, maximum principal stress, maximum Shear stress, etc.; stress has many states, such as stretching, bending, torsion, etc.; material strength has many types, such as tensile strength, compressive strength, bending strength, etc., which stress and which material to use Calculation of the ultimate load-bearing torque based on the strength is highly subjective, so that the calculation of the limit load-bearing torque varies greatly and has low precision, which cannot meet the needs of product development

② The safety factor evaluation comprehensively considers the impact of structural stress type, stress state and material strength corresponding to different stress states, etc., to a certain extent avoids the subjectivity of engineers, but the calculated ultimate bearing torque is far lower than the test value, which is relatively conservative, so that The physical prototype of the transmission housing has a large strength backup coefficient, heavy weight, and high cost, which seriously affects product competitiveness.

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