8 results about "Back stress" patented technology

Ceramic honeycomb bodies and methods for their manufacture are provided. The ceramic honeycomb body comprises a bulk density of less than 210 g / L, a geometric surface area (GSA) greater than 93 in−1 (3.66 mm−1), a mechanical integrity factor (MIF) greater than 0.28%, and a back pressure factor (BPF) greater than 0.4 mm2.

The high-precision stamping equipment comprises an upper die assembly, a lower die assembly, a female die, a punch and a back pressure mechanism, the female die is fixed to the upper die assembly and faces the lower die assembly, and a model groove matched with the punch in shape is formed in the side, opposite to the lower die assembly, of the female die; a circle of first protrusions matched with the model groove in shape are arranged on the periphery of the model groove. The punch is arranged on the lower die assembly and faces the model groove. The lower die assembly comprises a lower die base and a base plate arranged on the lower die base. The back pressure mechanism is fixed to the lower die base, and one end of the back pressure mechanism makes contact with the base plate. The device has the effect of improving the punching precision of general punching equipment.

These are individual walls (1) of modular dimensions with the confronting side edges (2) enabling the beveled finish to be mounted, so that the junction of four walls (1) at 90° create a modular junction box (3), each with a groove (8) at 90° and a rib (9) at 45° that enables assembly by sliding and double locking, configuring back pressure fittings between said walls (1).

This invention relates to the field of medium-high entropy alloy technology, specifically to a high-strength and high-toughness multi-level heterogeneous medium-entropy alloy and its preparation method. This invention discloses a CoNiVAlTa-based medium-entropy alloy, which, through compositional design and process adjustment, utilizes low-temperature pre-aging to induce metastable phase transformation, followed by high-temperature recrystallization to achieve grain refinement and precipitation of multi-level strengthening phases. By introducing multiple strengthening mechanisms—grain refinement strengthening, precipitation strengthening, and back stress strengthening—the material possesses both high strength and high plasticity. This series of alloys exhibits a tensile strength of 1460 MPa to 1615 MPa at room temperature and a fracture elongation of 15% to 27%. This high-strength and high-toughness multi-level heterogeneous medium-entropy alloy not only boasts excellent comprehensive mechanical properties but also features a simple and feasible process, demonstrating great promise for engineering applications.

The present application relates to a kind of fastening process fastening effect evaluation method considering internal stress, comprising: simulating the fastening process to be evaluated, fastening, unloading and reverse fastening are carried out to fastener sample, and the stress and strain of different time are obtained;Multiple stress and strain points in stress and strain coordinate system are obtained;According to the multiple stress and strain points of unloading and reverse fastening process, the elastic segment region of unloading and reverse fastening process is obtained;The maximum stress and minimum stress of each stress and strain point in the elastic segment region are obtained, respectively as the upper limit of elastic segment and the lower limit of elastic segment;The back stress of fastener sample is determined;According to the back stress of fastener sample, the fastening effect evaluation result of the fastening process to be evaluated is obtained.The fastening process fastening effect evaluation method considering internal stress of the present application uses the back stress of fastener sample to evaluate fastening effect, so as to consider the influence of fastening process on fastening effect, to accurately assess the fastening effect of fastener.

The application discloses a kind of ceramic matrix composite nonlinear stress-strain relationship evaluation methods, comprising the following steps: step 1. carry out the stress-strain relationship evaluation test of ceramic matrix composite;Step 2. according to test data, the parameters of anisotropic yield function and the evolution equation parameters of anisotropic back stress increment are determined;Step 3. by relevant plastic flow rule, inelastic strain is obtained;Step 4 and step 5 determine the elastic stress-strain relationship with damage;Step 6 selects the numerical simulation method based on incremental theory: complete implicit reflection algorithm is used as stress-strain relationship updating algorithm.The nonlinear stress-strain relationship evaluation method proposed in the application introduces back stress evolution to simulate the ratchet effect of ceramic matrix composite hysteresis loop under uniaxial cyclic loading, and the model is simple and easy to use, and the required test amount is small, which saves cost.

In the crystal plasticity finite element method, it was necessary to represent the crystal orientation in the data in order to determine the anisotropy caused by differences in crystal orientation. Furthermore, many finite element methods using yield functions exhibit isotropic hardening. [Solution] The crystal orientation was changed to represent the Taylor factor M. In other words, for a face-centered cubic lattice, the data for the 12-slip system could be rewritten in terms of the Taylor factor M. Furthermore, by including the deviated back stress, the Bauschinger effect could be expressed. This is not possible for rigid-plastic properties.