14 results about "Stress resultants" patented technology

The invention discloses a BIM (Building Information Modeling) and real-time monitoring-based cylindrical pier cast-in-place cantilever variable cross-section continuous beam bridge construction early warning system and method, and relates to the technical field of construction early warning. According to the system, alignment and noise reduction are carried out on monitoring data through BIM constrained drift correction, a curvature sequence and an acceleration sequence are obtained, an energy response index and an energy characteristic index are extracted, and a space-time distribution matrix is formed. And identifying a curvature deviation development trend by using a time sequence prediction model, and dynamically evaluating structural stress distribution and a deformation state in combination with finite element analysis. When the deviation value or the stress result exceeds a multi-level threshold value, finite element reanalysis is triggered for correction. And the decision execution module judges the real-time safety level and generates an early warning signal by integrating the monitoring characteristics and the simulation result based on a robust intelligent identification model subjected to ring loss regularization training. The method can improve the monitoring precision and robustness of the construction stage, and achieves the real-time, foresight and closed-loop management and control of the structure safety.

The invention discloses a concrete dam gallery arch part concrete cracking analysis method, which comprises the following steps: constructing a gallery arch three-dimensional finite element model, carrying out simulation analysis on a temperature field and a stress field in a dam gallery arch construction period, further evaluating the gallery safety state, analyzing the reason of foundation drainage gallery arch cracking, and determining the concrete cracking degree of the foundation drainage gallery arch. And finally, crack propagation simulation is performed on the gallery part based on a stress result, so that a scientific basis and feasible suggestions can be provided for formulating anti-cracking measures of the gallery in the construction period, the stress-strain process of the concrete at the top arch part of the concrete dam gallery is effectively monitored in real time, the cracking condition is analyzed, and the crack propagation path and trend are simulated. According to the method, a scientific basis is provided for revealing a concrete crack forming mechanism, key technical support is provided for anti-cracking reinforcement of the arch dam gallery top arch part through prospective risk pre-judgment, and controllability and reliability of structural safety in the concrete dam construction period are improved.

The application discloses a kind of composite material curing after re-perforation deformation prediction method, first use three-dimensional modeling software to establish the finite element model of not being perforated, and carry out mesh division;Adopt the method of complete thermal coupling, respectively through calculation to obtain temperature, curing rate, degree of cure, and stress result before demoulding;By converting the boundary condition of finite element model, through stress calculation method, the stress distribution result and displacement deformation result of finite element model after demoulding are recalculated, obtain the stress distribution result and displacement deformation result after demoulding;Then again mark the area needing to be perforated, and carry out stiffness reduction, release stress, realize the simulation to be perforated, through stress calculation method, the stress distribution result and displacement deformation result of finite element model after perforation are recalculated;Export the back result of component after perforation and the result before curing, with the aid of Geomagic Control software carries out high-precision fitting, obtains the final curing after perforation deformation result.

The application relates to the technical field of highway and railway bridge design, and discloses a corrugated steel web curved box girder torsional stress analysis method based on prestress effect, which comprises the following steps: S1, determining the mechanical characteristics of the corrugated steel web box girder bridge; S2, performing equivalent load processing on the prestress effect and performing reasonable simplification; S3, establishing a constraint torsion differential equation of the corrugated steel web combined curved box girder to obtain the constraint torsional normal stress and the constraint torsional shear stress of the required section; S4, combining the curved beam boundary conditions, the torsional double moment and the torsional stress formula of the box girder under various load conditions, adopting the initial parameter method to superimpose the boundary conditions into the general solution form of the constraint torsion differential equation of the corrugated steel web combined curved box girder, extracting the calculation data of the torsional stress of the corrugated steel web combined curved box girder, and analyzing to obtain the torsional stress result of the corrugated steel web combined curved box girder. The corrugated steel web curved box girder bridge torsional performance based on the prestress effect is researched by adopting the application.

The invention provides a virtual statics test system and test process double-level modeling evaluation method and system. The method comprises the steps that a parameterized geometric model of test system structural characteristics is established; constructing a simplified test system finite element model; calculating the structural mechanical response of the simplified test system finite element model under the action of the static test load; intercepting the structure of the high-stress area according to a calculation result, and performing integral calculation on resultant force and resultant bending moment on the cross section of the intercepted structure; establishing a refined finite element model containing all the features of the structural region, analyzing mechanical responses of all the feature structures of the structural region, and analyzing the mechanical responses of all the feature structures by taking resultant force and resultant bending moment on the cross section of the intercepted structure as load boundary conditions to obtain a stress result of the structure; and evaluating the strength failure risk of the structural system under the load effect in the test process. According to the method, the finite element analysis efficiency of a large-scale test system can be improved, and the test process risk can be evaluated in real time.

The invention provides a calculation optimization method for an arch and cross beam combined section of a separated steel truss girder arch bridge, and belongs to the technical field of civil engineering, and the method comprises the following steps: determining a shear-resistant section according to the arch and cross beam combined section structure and a force transmission path, and determining main shear-resistant plates and welding seams; setting constraint conditions, and calculating to obtain vertical and horizontal shear forces of the shear-resistant section; solving the shear stiffness of a shear resistant plate and a welding seam by utilizing a shear stiffness calculation formula of a connecting plate of the arch and the cross beam and the welding seam after correction, and distributing shear force to calculate the force transmission of the plate and the welding seam; calculating the average shear stress of the force transmission plate and the weld joint, constructing a shear stress function, and calculating the maximum shear stress; introducing a strength check coefficient to judge a shear stress result, and optimizing the thickness of a combined section plate and the number of partition plates to obtain a structure optimization scheme; the method solves the problems that an existing arch and cross beam combined section optimization calculation method is huge in workload, complex in process and long in structure checking calculation time.

The invention discloses a finite element analysis method for reducing concrete tensile stress through a transverse joint grouting measure. Comprising the following steps that a concrete gravity dam discharge dam section and foundation model is established, finite element software is imported, and numerical simulation parameters are set; grid division is carried out on the model, and grids in the runner are encrypted; constraint and load are applied, elastic support is applied to the side surface of the dam section, and transverse joint grouting measures are simulated; and solving the model by using finite element software, and evaluating stress results of an inlet section, a gate slot section and a breast wall section of the discharge dam section. The device has the advantages that elastic support is applied to the side surface of the dam section, and the effect of transverse joint grouting measures on the dam section is simulated. Quantitative calculation results show that transverse joint grouting measures can increase the lateral rigidity of the dam section, improve the stress state of concrete and reduce the tensile stress of the concrete in the flow channel, so that the use amount of steel bars in the flow channel is reduced, and the method is safe, economical and convenient to construct.

This invention belongs to the field of water turbine technology, and specifically relates to a method and structure for shaping the root of an impulse turbine bucket. The shaping method includes the following steps: the middle and both sides of the bucket root are connected to the curved surface of the bucket using cylindrical surfaces; boundary conditions and loads are applied, and finite element analysis is performed on the bucket; based on the stress results, the bucket root is divided into a high-stress zone in the middle and general stress zones on both sides; auxiliary sections and control lines are added to the high-stress zone, and a saddle-shaped stress-reducing structure with a truncated top is constructed using curve groups or curve meshes; the saddle-shaped stress-reducing structure is connected to the front and back sides of the bucket root in the general stress zone by rounding; the saddle-shaped stress-reducing structure is bridged to the cylindrical surface of the general stress zone using bridging surfaces. This invention provides a method and structure for shaping the root of an impulse turbine bucket that can effectively reduce the stress level in the high-stress zone of the bucket root, enhance its versatility and operability, and reduce the development cycle of the bucket.

The present application relates to the technical fields of engineering structure mechanics, and discloses a kind of analytical calculation method of section internal force of thin-walled member, comprising the following steps, step S1: according to the basic composition of thin-walled member section stress, the member section stress σ is split into axial force normal stress σ N , bending normal stress σ M , constraint torsion normal stress σ T ;Step S2: according to the distribution law of various stresses on the thin-walled member section, the member section axial force N and axial force normal stress σ N ;Step S3: the member section stress σ is subtracted from axial force normal stress σ N ;Step S4: calculate bending normal stress σ M ;Step S5: according to the bending normal stress σ M solved by S4, solve the effective section characteristics of member;Step S6: solve section bending moment M.The present application compared with prior art, can be used for the thin-walled member internal force test in the fine plate shell or solid finite element model and actual structure, obtain internal force from stress result, suitable for open section and closed section thin-walled member simultaneously, solve the problem that thin-walled member section internal force is difficult to obtain.

The invention discloses a design method for reducing concrete tensile stress by adjusting a water stop position, and particularly relates to a design method for effectively reducing the tensile stress in a flow channel of a concrete gravity dam by reasonably adjusting water stop arrangement. Comprising the following steps that a concrete gravity dam discharge dam section and foundation model is established, finite element software is imported, and numerical simulation parameters are set; grid division is carried out on the model, and grids in the runner are encrypted; constraint and load are applied to the target analysis dam section, the water stop position of the side face of the target analysis dam section is adjusted, hydrostatic pressure is applied, and a reasonable water stop arrangement type is achieved through repeated adjustment; and solving the model by using finite element software, and evaluating a stress result in the flow channel of the discharge dam section. The hydrostatic pressure is applied to the side surface of the dam section to simulate the influence on the stress of the dam section after the water stop position is adjusted. The design method shows that the tensile stress in the concrete gravity dam flow channel can be reduced by adjusting the water stop position, and therefore the use amount of steel bars is reduced.

The invention relates to the technical field of structural stress analysis, in particular to a grid insensitive fillet weld fracture structural stress analysis method and system, and the method comprises the steps: building a structural model comprising weld connection by using finite element software; a working load is applied to the structure model, the structure model after the working load is applied is solved, and overall stress distribution and nodal force information of the structure are obtained; defining a cutting path perpendicular to the substrate at the welding root of the model, and extracting a stress result of the cutting path by utilizing a post-processing function of finite element software; according to the stress result and the weld leg size, the traction stress component under the cutting plane angle is calculated through a formula; traversing cutting plane angles in a formula, and determining a critical failure plane and a maximum stress value corresponding to the critical failure plane; and performing fatigue life evaluation and weld joint structure optimization based on the maximum stress value. According to the method, the calculation efficiency and the engineering applicability are improved, and a reliable basis is provided for standardized and intelligent design of welding seam fatigue evaluation.

The application discloses a heavy machinery equipment structural member fatigue calculation method, system, equipment and medium, and the method comprises the steps of: selecting a plurality of characteristic loads of envelope time sequence loads according to the nonlinearity degree of the structure; segmenting the time sequence loads, and generating a load ratio file corresponding to each characteristic load; performing finite element loading calculation on the characteristic loads, and obtaining a stress result file for piecewise interpolation curve; obtaining the stress time sequence under each time sequence load by combining the load ratio file and the stress result file; performing rain flow counting on the stress time sequence to obtain the number of stress amplitudes and mean values, and then obtaining the fatigue damage of the structural member by combining an SN curve. Through the segmentation processing of the time sequence loads, finite element analysis is performed on each load step, the relationship between the nonlinearity degree of the structure and the stress response of the structure is considered, the stress time sequence and the fatigue damage of the structural member can be obtained with higher accuracy, and the occurrence of overdesign or excessively aggressive design and the like can be prevented.

Systems and methods described herein are configured to estimate nominal stress using finite element (FE) stress calculations, without hand calculations, specific mesh density requirements, or identifying specific geometric parameters such as plate thickness. The systems and methods described herein may be utilized to identify nominal stress in welded structures and components, and also in non-welded components that have stress raisers due to other causes. The systems and methods described herein also allow readily available FE stress results to be utilized in a consistent manner, as well as providing user feedback regarding the accuracy of the nominal stress approximations. Furthermore, the systems and methods described herein are generally faster and less error prone than conventional techniques, and are relatively insensitive to mesh density of the FE stress calculations.