4 results about "Characteristic length" patented technology

This invention discloses an online uniformity monitoring method and system for TMR mixing process based on dynamic particle morphology recognition, relating to the field of intelligent monitoring technology in feed processing. The method includes: during material mixing, real-time acquisition of dynamic images of the material within the mixing chamber; identification of material particles in the dynamic images; extraction of the characteristic length of each particle; and calculation of skewness and kurtosis based on the characteristic length; division of the effective observation area of ​​the dynamic images into multiple sub-regions based on the centroid coordinates of all material particles in the dynamic images; extraction of particle characteristic statistics within each sub-region; and construction of a multidimensional spatial uniformity index set to characterize the mixing state of the material; input of the skewness, kurtosis, and multidimensional spatial uniformity index set into a pre-trained evaluation model, outputting a comprehensive uniformity index and corresponding quality level.

The invention provides a rock dynamic shear failure simulation method and equipment considering frictional contact. The method comprises the following steps: calculating a stress tensor and a four-order elastic modulus matrix according to an elastic constitutive relation of a rock material; establishing a crack surface local coordinate system based on a maximum shear stress criterion, and determining normal and tangential unit vectors; introducing a crack density function and a corresponding degradation function of the cohesion phase field model, and configuring to eliminate the influence of the phase field characteristic length; deducing an energy functional of a dynamic shear phase field model, judging a contact state according to normal strain of a crack surface, and deducing strong forms of a displacement field control equation and a phase field control equation; variational processing is conducted on the strong forms of the displacement field control equation and the phase field control equation, corresponding weak forms are obtained, rock dynamic shear failure simulation considering frictional contact is achieved based on the weak forms, and rock mass stability evaluation in geological disaster prevention and control is supported. The model is insensitive to the phase field characteristic length, and the simulation result is more reliable.

The application discloses a kind of composite laminated plate strength calculation methods considering the size effect of opening, belong to the technical field of composite laminated plate.The present application is in view of the problem that existing prediction method relies on a large number of layer-specific test or complex numerical model, through a set of standard opening plate tensile test, combined with the basic mechanics parameters of unopened laminated plate, first calculate the characteristic length of standard plate and 0 ° layer strain energy release rate, and then establish the strain energy release rate conversion relationship between any orthogonal layer, finally realize the accurate prediction of the strength of any orthogonal layer, different aperture opening plate.This method greatly reduces the number of tests and cost, avoids the unconventional test such as fracture toughness, and is completed based on analytical formula throughout, high precision, simple operation, easy to apply and popularize in engineering practice.

The invention discloses a quantitative evaluation method for rock mass integrity, which comprises the following steps: S1, carrying out rock mass and rock mass wave velocity test on representative drill holes in an engineering area, and determining the rock mass integrity of the engineering area; s2, performing statistics on rock core lumpiness of different rock mass integrity degrees to obtain feature lengths corresponding to the rock mass integrity degrees; s3, calculating a rock core lumpiness index correction value according to the characteristic length corresponding to the integrity degree of each rock mass; and S4, dividing the final rock mass integrity degree of the engineering area according to the rock core lumpiness index correction value. According to the method, the problem that rock mass integrity indexes of partial areas cannot be obtained in the prior art, and then rock mass integrity evaluation is deviated is solved, compared with the prior art, the statistical range of the rock core lumpiness index correction values can cover all coring and drilling holes in an engineering area, the number source is more complete and objective, and meanwhile excessive economic input does not need to be increased.