35 results about "Shear strain rate" patented technology

The present invention teaches formulations, apparatus and a method of applying high thixotropic index polymer thick-film resistive pastes for making polymer thick-film resistors with improved tolerances by providing a squeegee with a blade tilted at an angle of 10° to 85° to the surface of the printed circuit board thus causing a fluid rotational motion within the bead of the polymer thick-film resistive paste as the squeegee blade moves relative to the printed circuit board. This rotational motion increases the shear strain rate experienced by the paste within the bead and results in a more effective filling of the resistor-shaped cavity without including air bubbles, experiencing elastic recovery of the paste and, without surface fractures of the paste.

An extensible nonwoven fabric comprises a fiber comprising at least two olefin-based polymers. These olefin-based polymers are of the same kind and have different induction periods of strain-induced crystallization as measured at the same temperature and shear strain rate. A composite nonwoven fabric of the invention comprises at least one layer comprising the extensible nonwoven fabric.

A method of designing a roller bearing is disclosed upon clarifying mechanisms of damage patterns in respect of two kinds of brinelling, involved in the bearing, wherein white-banded flaking (brittle flaking) is a plastic instability phenomenon appearing under high-speed deformation accompanied by adiabatic shear deformation status with the resultant occurrence of adiabatic shear band (also called white band) inside material of the bearing. This enables all of the damage patterns to be determined upon making comparison between shear strain and shear strain rate, occurring inside the bearing, and discriminated values.

A micro-nano fluid damper includes a sleeve, a piston assembly and a micro-nano fluid. The sleeve has an accommodating space. The piston assembly has a piston head and at least one piston rod. The piston assembly is movably disposed in the accommodating space. The piston rod extends out of the sleeve from a side of the piston head. The micro-nano fluid is filled between the sleeve and the piston assembly, and the micro-nano fluid flows in the accommodating space by the back-and-forth movement of the piston. When a shear strain rate of the micro-nano fluid is greater than 1s−1, an exponent of velocity of the micro-nano fluid damper is less than 1, and the micro-nano fluid has a shear thinning threshold and a shear thickening threshold.

The invention belongs to the technical field of internal mixer rotors, and relates to a meshing and shearing variable-gap hexagonal rotor, which is installed on an internal mixer and used for mastication and mixing of rubber. It consists of a rotor body and six rotor bodies. The front and rear rotors are meshed and connected by ribs and returning glue threads. When in use, the front and rear rotors are sleeved on the screw. The screw absorbs the advantages of the meshing and shearing mixing rubber, overcomes the shortcomings of each other, and strengthens the rubber in the rubber. The axial movement in the mixing chamber improves and strengthens the shear capacity between the ridge peak and the wall of the mixing chamber; with sufficient shear force, a high shear strain rate is achieved, and sufficient rubber movement ensures The uniformity of the mixing and dispersion of the rubber material is ensured. At the same time, the setting of the glue return thread can prevent the rubber material from overflowing in the internal mixer. Compared with the standard four-edged rotor, a short edge is added on one side of the front rotor and the rear rotor, which is beneficial The backflow of the rubber material makes the lateral movement of the rubber material in the mixing chamber more obvious, which is more conducive to the mixing of the rubber material.

The invention provides an improved powder injection molding shot, its manufactured product and product manufacturing method, wherein the improved powder injection molding shot includes: sinterable powder and a binder, the binder includes a hydrocarbon wax, a surfactant, Polyolefin compounds, polyoxymethylene, and rheology modifiers. The powder injection molding shot of the present invention contains a rheological modifier to reduce the powder injection molding shot from becoming an expansion fluid in the high shear strain rate (high shear rate) region, thereby maintaining a high injection rate. In the case of speed, increase the quality of the product.

The invention discloses an ultrahigh shear strain rate lubricating grease rheological model. The formula is shown in the description. The model is convenient to construct, parameters on which the model is based are easy to obtain, the model is measured on an ultrahigh shear train rate rheometer, and it is verified that the model has high precision and is especially suitable for rheological data with the shear strain rate from 0 to 3.5*106 s<-1> and even higher. The model has high applicability, and is suitable for solving lubricating grease shear strain between any two contact parts rolling relatively and sliding. After the model is built, the model can be used for solving the friction force of lubricating grease integrally, and the friction force of the lubricating grease is an important parameter necessary for lubricating grease research and development and bearing design. The model has high applicability especially on complex lithium-based grease.

The invention discloses a method for controlling the crystallization of α-olefin homopolymer through processing conditions, and belongs to the technical field of polymer crystallization. The long-chain α-olefin homopolymer with 12-20 carbon atoms is heated to 160°C and kept for 10 minutes, and the temperature is lowered so that the long-chain α-olefin homopolymer crystallizes to obtain the initial sample; then the temperature is raised to 45-160°C to melt and Keep warm for 1-3600s, then cool down to an isothermal temperature of 10-75°C at 10°C / min; apply a shear strain rate of 0-5s ‑1 , a flow field with a shear time of 0‑5s, and crystallization at the isothermal crystallization temperature. In the present invention, there are obvious differences in the crystallization time of long-chain α-olefin homopolymers under different processing conditions, which shows that processing conditions have a greater impact on the crystallization time of long-chain α-olefin homopolymers, and provides a basis for improving processing and molding efficiency. a feasible solution.

The invention discloses a vehicle bumper. The vehicle bumper comprises a packaging layer, a mounting plate, a fixing ring, a forward lever, a reverse lever, a short rotating shaft, a long rotating shaft, a T-shaped sliding block, a guide rail, a fastening screw, an STF, an end cover, an anti-collision beam support frame and a shear effect increasing device. The vehicle bumper has the characteristic of superior cushion protection performance, can be widely applied the field of collision protection of vehicles to reduce the casualty rate of personnel and property loss. By combining STF and multi-link structure, the good energy absorption characteristic of the STF is used and the kinetic characteristic of a multi-link structure is also used so that when shock occurs, other STFs around are driven to participate in the energy consumption process, the utilization efficiency of the STFs is improved, and energy absorption efficiency of the STF is greatly improved. The STF has a sensitive and rapid response to the shear strain rate so that the bumper can make a high energy consumption response at the moment the bumper is shocked, the protective performance of the structure is improved and the complexity of the whole structure is reduced.

The invention discloses a method for establishing a crystal plastic constitutive model in the fatigue process of a face-centered cubic material. The invention solves the problem that mesoscale plastic evolution and material microstructure characteristics cannot be considered in the calculation of material damage and fatigue failure, and provides a more accurate and innovative mesoscopic crystal modeling method and crystal plastic constitutive model and related stable and efficient calculation method. The crystal plastic constitutive model and calculation method proposed by the present invention take into account the normal direction and slip direction of the crystal slip surface, use the motion and isotropic hardening criteria to consider the back stress effect, and finally establish the crystal slip and dislocation density and plastic shear A constitutive model for crystal plasticity of face-centered cubic metallic materials as a function of shear strain rate. It can study the influence and contribution of material microscopic characteristics on material damage and fatigue life from the mesoscopic scale, and provide important theoretical guidance and technical support for the study of material damage evolution and fatigue failure process, which has important scientific significance and engineering application value.

The invention discloses a horizontal annular slot type test device for a magnetorheological material, which comprises a frame, wherein a magnetic field generating device, a shearing mechanism, a shearing strength detection mechanism, a warming and temperature detection mechanism, a lifting mechanism and a control system are arranged on the frame. Compared with the traditional test device, the horizontal annular slot type test device for magnetorheological material provided by the invention is additionally provided with the warming and temperature detection mechanism, so the device can be usedfor testing the influence of temperature on the magnetorheological liquid property. The three factors (temperature, magnetic field intensity and shearing strain rate) influencing the magnetorheological liquid and the change gradient of the three factors can be controlled, so the property parameters of the magnetorheological liquid can be more comprehensively detected. The shearing mechanism of the device can be used for furthest concentrating the shearing strength between a fixing ring and a shearing ring at the position of the magnetorheological liquid, thereby ensuring an accurate testing result and acquiring a better testing effect.