10 results about "Relaxation modulus" patented technology

The present application provides a method and apparatus for determining the dimensions of a mandrel, a device, a medium, and a product. The method comprises: establishing a cross-sectional model of a pipe on the basis of dimensions of an initial mold, performing mesh discretization of the cross-sectional model of the pipe, then assigning a shear relaxation modulus function to each mesh cell, and obtaining a viscoelastic model of the pipe; on the basis of an actual stress and an actual temperature field, performing deformation simulation on the viscoelastic model, and obtaining a deformation model of the pipe; and obtaining optimized mandrel dimensions on the basis of a comparison result of the cross-sectional model and the deformation model. In the solution of the present application, the cross-sectional model is established on the basis of dimension requirements of the pipe, the viscoelastic model can characterize the relaxation modulus of the pipe under shear stress, and the environmental conditions of the pipe during a cooling and solidification stage can be extracted using the actual stress and the actual temperature field, thereby improving the accuracy of deformation simulation and mandrel dimension adjustment and accordingly enhancing the anti-sag performance of the pipe.

The invention provides a rubber stress relaxation test method and system suitable for finite element simulation, and relates to the technical field of rubber material mechanical property tests.The method comprises the steps that tensile relaxation test data and compression relaxation test data of a rubber sample are obtained; preprocessing the tensile relaxation test data and the compression relaxation test data to obtain preprocessed stress-time data; performing curve fitting based on the preprocessed stress-time data to generate a stress relaxation curve; performing fitting analysis on the stress relaxation curve by utilizing a viscoelastic model, and extracting relaxation time and relaxation modulus for representing the viscoelastic behavior of the rubber material; and inputting the relaxation time and the relaxation modulus into finite element simulation software for tire performance simulation. According to the test method and system, the specific test process and standardized data processing are combined, and high-precision and high-reliability parameter transmission from a physical test to a simulation model is achieved.

The invention relates to a method and a device for determining vibration simulation modeling parameters of a battery pack structural adhesive. The method comprises: based on a structural adhesive built in a battery pack, obtaining frequency scanning data of the structural adhesive, the frequency scanning data comprising at least two scanning frequencies, and energy storage moduli and loss moduli corresponding to the scanning frequencies; then, determining a relaxation time set based on all scanning frequencies, and determining a fitting modulus set based on the relaxation time set, the frequency scanning data and a preset modulus equation so as to accurately simulate modulus states of the structural adhesive at different frequencies (such as a stress hysteresis phenomenon caused by the fact that molecular movement in a material cannot keep up with rapid change of external force); and then, based on the fitting modulus set, the material type of the structural adhesive and the constant Poisson's ratio, determining a relaxation modulus set, and based on the relaxation modulus set, the relaxation time set and the constant Poisson's ratio, determining vibration simulation modeling parameters of the structural adhesive so as to effectively guarantee the accuracy of a vibration simulation result during subsequent simulation processing.

The application discloses a kind of viscoelastic material relaxation modulus testing device, including bottom channel steel, bottom channel steel is equipped with fixed screw rod, L type support seat;Fixed screw rod top fixed connection is equipped with fixed end coupling, fixed end coupling is horizontally equipped with lever, and is hinged between fixed end coupling and lever by fixed end pin;L type support seat is fixedly equipped with ball screw sliding table assembly.The application has the advantages compared with prior art: simple structure, convenient to use.The high-speed rotation of stepper motor, the linear motion of sliding table, the low-speed vertical linear motion of loading rod, the spherical indenter is driven into the measured viscoelastic material, and the stress response of the material to the specific strain loading is measured by the pull pressure sensor.The movement law of the indenter is indirectly monitored by the eddy current displacement sensor whether it meets the experimental requirements.Therefore, the relaxation modulus of different viscoelastic materials can be tested and studied, and the parameterization characterization of the relaxation modulus of different viscoelastic materials is realized.

The invention provides a core mold size determination method and device, equipment, a medium and a product, and the method comprises the steps: building a cross section model of a pipeline according to the size of an initial mold, carrying out the grid division of the cross section model of the pipeline, endowing each grid unit with a shear relaxation modulus function, and obtaining a viscoelastic model of the pipeline; performing deformation simulation on the viscoelastic model according to the actual stress and the actual temperature field to obtain a deformation model of the pipeline; and according to a comparison result of the cross section model and the deformation model, obtaining an optimized core mold size. According to the scheme, the cross section model is established according to the size requirement of the pipeline, the viscoelastic model can represent the relaxation modulus of the pipeline under the shear stress, the environmental conditions of the pipeline in the cooling and solidification stage can be extracted through the actual stress and the actual temperature field, the accuracy of deformation simulation and core mold size adjustment is improved, and the production efficiency is improved. Therefore, the sagging resistance of the pipeline is improved.

The invention relates to the technical field of polymer packaging material viscoelasticity constitutive model testing, in particular to an improved polymer packaging material viscoelasticity constitutive model testing and fitting method.The method includes the steps that an actual stress relaxation curve and a main curve are subjected to overlapping mean value re-fitting, and the shape and parameters of the main curve are optimized; replacing the energy storage modulus translation amount with the relaxation modulus translation amount to optimize a shift factor; an interpolation method is adopted to replace a WLF equation in numerical calculation, so that the input precision is improved; sample errors and human experience errors are reduced from multiple links of testing, fitting and numerical calculation, and fitting deviation of a WLF equation is eliminated, so that the model keeps high precision in a wider temperature range, and closed-loop verification of viscoelasticity testing is realized; a high-precision material test engineering scheme is provided for advanced electronic packaging, the production loss is reduced, the prediction capacity for packaging signals, heat transfer and stress is remarkably improved, the product yield is increased, the service life is prolonged, and the long-term reliability is improved.

The present invention relates to a polyvinyl acetal film comprising a reduced amount of plasticizer having an improved shear relaxation modulus.

The present application relates to the field of material science, disclose a kind of asphalt concrete pavement section joint crack resistance method and system based on net taste technology, the method comprises: fitting the pavement section joint model of section joint;Analysis of the damage zone and fracture zone of pavement section joint model, analyze the material stiffness modulus and material relaxation modulus of asphalt concrete;Construction of the viscoelastic damage model of asphalt concrete, calculate the viscoelastic damage coefficient of asphalt concrete, analyze the asphalt viscoelasticity of asphalt concrete;Fitting the crack analysis model of section joint, simulate the pavement damage evolution of section joint;Chemical additives and asphalt concrete are mixed, analyze the viscous effect of geotechnical mixture material;Determine the optimum elastic modulus of geotechnical mixture material, analyze the crack resistance effect of geotechnical mixture material, execute the crack resistance scheme of corresponding section joint of asphalt concrete pavement.The present application can improve the crack resistance effect of asphalt concrete pavement section joint.

This invention relates to the field of polyethylene pipe technology, and in particular to a method for calculating the strain of high-density polyethylene pipes based on relaxation modulus. The method provided by this invention measures the relaxation modulus G of high-density polyethylene material at different times. t And based on the relaxation modulus G of high-density polyethylene material at different times. t The scalar coefficient G0, along with the temperature-sensitive factors φ and α of the modulus, are obtained. Finally, the strain ε of the high-density polyethylene (HDPE) pipe sample is calculated using the scalar coefficient G0 and the temperature-sensitive factors φ and α of the modulus. The method provided by this invention can predict and improve the anti-sagging performance of HDPE pipes and can be further applied to nuclear power plants, municipal construction, and other fields requiring high-performance polyethylene pipes.

According to an embodiment of the present invention, there is provided a contact lens package comprising: a package having a cover member and a bottom member; and a contact lens housed in a deformed state in a housing space sealed by the cover member and the bottom member, the contact lens having a relaxation modulus of 1.6 MPa or less. The relaxation modulus of the contact lens is an elastic modulus after one second elapsed from the start of measurement when the stress necessary for holding the contact lens is measured while applying a strain of 75% with respect to the upper limit of a linear elastic region in a tensile test to the contact lens in a 35 DEG C aqueous medium.