33 results about "Hydrostatic stress" patented technology

The present invention relates to a float collar apparatus for regulating the passage of fluid through a drilling / production liner or sub-sea casing. Apparatus of the present invention is fabricated using plastic flapper valves and valve-actuating sleeve components in contrast to prior art float collar components which are fabricated almost entirely of hard metals. Particularly, the plastic may be nylon, phenolic, or a phenolic-nylon laminate. The use of plastic components in the float collar apparatus of the present invention provides a substantial reduction in time and resources expended during drilling out of the float collar once cementing operations are completed. Additionally, the float collar apparatus of the present invention is fabricated from a pre-determined combination of plastic components and metal components thereby ensuring that the improved float collar can still endure substantial hydrostatic stresses encountered during casing liner running in and cementing operations.

The present invention relates to a float collar apparatus for regulating the passage of fluid through a casing liner or sub-sea casing. Apparatus of the present invention is fabricated using plastic flapper valves and sleeve components in contrast to prior art float collar components which are fabricated almost entirely of hard metals. The use of plastic components in the float collar apparatus of the present invention provides a substantial reduction in time and resources expended during drilling out of the float collar once cementing operations are completed. Additionally, the float collar apparatus of the present invention is fabricated from a pre-determined combination of plastic components and metal components thereby ensuring that the improved float collar can still endure substantial hydrostatic stresses encountered during casing liner running in and cementing operations.

A vibration isolation structure is provided with a stress reduction section that can reduce the hydrostatic stress from tensional load along a stacking direction of portions of a composite laminated member corresponding to a first end side and a second end side in a shear direction orthogonal to the stacking direction to lower than the hydrostatic stress from tensional load along the stacking direction of other portions of the composite laminated member.

Provided is a method for manufacturing a mechanical part (7) which has a rolling portion (6) on which a rolling element rolls and which is excellent in rolling fatigue life. An annular blank (2) to form the rolling portion (6) is subjected to cold forging by applying hydrostatic stress onto an inner diameter surface (2a) of the annular blank (2), whereby the rolling portion (6) on which the rolling element rolls is formed on the inner diameter surface (2a) of the annular blank (2) and the inner diameter of the portion of the annular blank (2) other than the rolling portion (6) is increased. Thus, an interface state between non-metallic inclusions contained in the steel material of which the annular blank (2) is made and the steel material, which is the matrix phase, is improved, and the annular mechanical part (7) having on the inner diameter portion the rolling portion (6) which is excellent in rolling fatigue life is manufactured.

Aspects of the invention relate to techniques for determining the electromigration features corresponding to layout design data. According to various examples of the invention, a circuit design is analyzed to determine voltages of nodes in an interconnect tree. From the voltages of the nodes, current density values and current directions for the segments of the interconnect tree are determined. Based on the current density values and the current directions, hydrostatic stress values for the nodes are computed under a steady-state condition and conservation of the conductive material within the interconnect tree. The electromigration susceptibility of the interconnect tree is then determined based on the computed hydrostatic stress values.

The invention discloses a method for predicting sheet forming fractures based on a damage fracture standard numerical value. The method includes the steps of obtaining the stress state distribution of a metal sheet cylindrical piece in the stamping process according to the thermodynamics irreversible law, obtaining a stress balance differential equation of the metal sheet cylindrical piece in the stamping process according to the stress state distribution, calculating the change rate, occurring when the metal sheet cylindrical piece is damaged, of the area of a small unit of the metal sheet cylindrical piece in the stamping process according to the continuum damage mechanics theory, obtaining the damage to the metal sheet cylindrical piece according to the change rate, calculating the relation between the damage and the strain of the metal sheet cylindrical piece, and finally deriving the relation between the damage value and the true stress, true strain and hydraulic stress of the metal sheet cylindrical piece under the unidimensional scale in the whole stamping process. By means of the method, the technical problem that when fractures during sheet forming are predicted through an existing numerical value method, errors are large can be solved.

A method is given for fracturing a formation, in particular far-field in a tight formation, in which at least a portion of the proppant is crushable in situ at some point during pumping, during fracture closure, or at higher stresses experienced later during fracture closure. The closure stress or hydrostatic stress is estimated, then a proppant is selected that is at least partially crushable at that closure stress, and then the fracturing treatment is performed with at least a portion of the total proppant being the selected crushable proppant.

A system and method measuring subterranean stress. The system and method includes a non-destructive sheath enveloping a tubular structure positioned in direct contact with a lateral subterranean rock formation for sensing expansive changes in the subterranean rock formation. A fiber optic is directly embedded in the non-destructive sheath positioned adjacent to the exterior surface of the tubular structure. The fiber optic transmits light and thereafter receives light in proportion to the expansive changes in the subterranean rock formation. A spectrometer connected to the fiber optic remote from the non-destructive sheath. The spectrometer measures hydrostatic stress in the subterranean rock formation without estimating acoustoelastic effects or occluding the tubular structure.

The present invention proposes a titanium alloy fine-blanking forming method. For TC4 titanium alloys of different thicknesses, fine-blanking is carried out by using finite element and experimental methods to obtain blank holder force, anti-deterministic force and stamping speed. The influence relationship of the hydrostatic pressure stress in the cutting strip, and then use the fracture criterion to judge the cracks under the hydrostatic pressure stress. Through a large number of experiments and simulation data fitting, the blank holder force and anti-bracket force obtained in the patent are obtained. The design relationship curve of force and blanking speed can be used to obtain the optimal combination of blank holder force, reverse jacking force and blanking speed, that is, the blank holder force and reverse jacking force increase continuously with the fine blanking process. , the punching speed is continuously reduced, so that the material in the shear zone is always in a good hydrostatic stress state, and a good shear bright zone is obtained. The invention realizes the fine blanking forming of the titanium alloy material, has high production efficiency, high utilization rate of raw materials, and good surface quality of formed parts.

The invention provides a monitoring method for creep deformation design of a high-temperature part of a thermal power generating unit. The monitoring method specifically comprises the following steps: inputting a material mark of the high-temperature part; determining service years m of the high-temperature part; determining annual average running hours t of the high-temperature part; calculating total running hours t0 of the high-temperature part; calculating principal stress and maximum principal strain of the high-temperature part; calculating equivalent stress sigma<eq> of the high-temperature part; calculating hydrostatic stress sigma<h> of the high-temperature part; calculating a correction factor A of multi-axial creep of the high-temperature part; determining design monitoring amounts of creep deformation of the high-temperature part; recognizing surface characteristic parts of the high-temperature part; conducting optimization control of creep deformation of a first class of surface characteristic parts; conducting optimization control of creep deformation of a second class of surface characteristic parts; printing output results. The monitoring method for the creep deformation design of the high-temperature part of the thermal power generating unit realizes quantitative prediction and design monitoring of the creep deformation of the high-temperature part of the thermal power generating unit.

The disclosed method of making a length of pipe can produce a fatigue resistant length of pipe having a relatively high fatigue resistance and a relatively small strip-to-strip weld length. Fatigue resistance is calculated from an experimental setup with control parameters and / or a simulation replicating similar material properties and loading conditions. High fatigue resistance means that certain product characteristics, such as low plasticity, low hydrostatic stress levels and defect-free welds, can be maintained after a specific number of tested cyclic loadings with adequate weld offset design at low values. The relatively small strip-to-strip weld length reduces the likelihood of crack initiation and / or propagation at weld locations where defects and local differences in mechanical properties often cause failure. Small strip-to-strip weld lengths can also reduce weld costs.

The invention discloses a plastifying fine blanking formation technology design method based on crack initiation control. The method comprises the following steps that according to the fracture criterion of fine blanked materials, critical hydrostatic stress during crack initiation of plates is obtained; in the fine blanking process, edge pressing force, blanking force and counter ejection force are exerted on an edge pressing ring, a male die and a counter ejection plate, and the counter ejection force is increased along with increase of the blanking stroke; when the blanking stroke initial position 0 travels to the blanking stroke position S1, the edge pressing force is increased gradually, when the blanking stroke position S1 travels to the blanking stroke, in the finishing process, theedge pressing force is reduced gradually, and when the blanking stroke reaches the stroke position S1, the plates reach the critical hydrostatic stress. According to the method, the effect of restraining crack initiation is restrained, fine blanked parts with full euphotic belts are obtained, thus energy consumption in the fine blanking process is reduced, the forming quality of the parts is improved, the service life of the die is prolonged, and the good comprehensive economic benefits are obtained.