86results about How to "Avoid fatigue cracking" patented technology

A multiplex fluid pump assembled from a plurality of pump bodies connected side by side between opposing end plates with a plurality of fasteners tightened to compress the pump bodies between the end plates. Raised surfaces on opposite exterior side surfaces of each pump body are engaged with an adjacent end plate or an adjacent pump body to apply a pre-compressive force at the raised surfaces and thereby inhibit the initiation of fatigue cracks.

The invention discloses novel high viscosity asphalt and a preparation method thereof. The novel high viscosity asphalt comprises the following raw materials in parts by weight: 100 parts of base asphalt with high asphaltene content, 0.1-1.2 part of polyphosphoric acid, 2-12 parts of a ductility improver mother liquid, 1-8 parts of a dispersant, and 0.2-0.5 part of a coupling agent. The preparation method comprises the following steps: adding the polyphosphoric acid in the molten base asphalt to perform a chemical modification reaction, then adding the ductility improver mother liquid, continuing to react, and finally adding the dispersant and the coupling agent to continue to react for a period of time to prepare high viscosity asphalt, wherein the whole process is performed under a highs-speed stirring condition. The high viscosity asphalt is high in 60-degree dynamic viscosity, high in softening point, high in low-temperature ductility, stable to store, and good in adhesion to aggregates, has excellent high temperature stability, excellent low temperature anti-cracking performance, excellent anti-fatigue performance and excellent water resistance, is especially suitable for high-temperature humid areas, areas with relatively high diurnal temperature difference, and paving of heavy-duty roads and drainable pavements, effectively prevents common pavement damages such as pavement rutting, pavement upheaval, pavement fatigue cracking, pavement cold cracking and water encroachment on pavements, and prolongs the service life of the pavement.

A vibration mode control method for a thin plate-reinforcement structure utilizes a reinforcing effect of a weld bead, wherein the thin plate-reinforcement structure comprises two welded components at least one of which includes a thin plate portion. After a first (thin plate) component and a second (another) component are arc-welded discontinuously at several positions, a stress direction and level in one of the resulting weld areas located to be subject to stress concentration is preliminarily verified. Then, a stress-dispersing weld bead (f) is laid to extend between the weld area which is an area subject to stress concentration and the first (thin plate) component, wherein the stress-dispersing weld bead (f) is set to a direction and length capable of preventing fatigue crack from occurring in the first (thin plate) component.

A threaded pipe connector, including: a pipe body including an external thread on one end; and a coupling including an internal thread on a corresponding end. Both the external thread and the internal thread are buttress threads capable of matching with each other. A ratio of thread height to pitch is 0.25-0.35, bearing surface angle is −15-3°, and guide surface angle is 10-50°. A clearance is provided between a thread crest and a thread root after engagement of the external and internal threads. A sealing area between the pipe body and the coupling includes in sequence a first cylindrical transitional area, a cylindrical sealing area, a secondary cylindrical transitional area, a conical sealing area, and a conical transitional area. Tapers of both sides of the conical sealing area are the same. One end of the conical transitional area is connected with a torque shoulder.