12 results about "Tensile fatigue" patented technology

To predict a fatigue life of a thermoplastic resin capable of improving prediction accuracy in a range where a stress ratio R is 0 to 1.SOLUTION: A fatigue life prediction method comprising a step of creating a fatigue life prediction diagram of a thermoplastic resin having a stress ratio R of 0 to 1 based on the following formula (1). Where σ a is a stress amplitude, σ m is a mean stress, σ B is a value based on a rupture strength calculated from a result of a tensile test with a stress ratio R of 1, an index x is a value of more than 0 and less than 1.0, and σ w is an intercept obtained by substituting, into the above formula (1), a stress amplitude and a mean stress calculated from a result of a pulsating tensile fatigue test with a stress ratio R of 0 as σ a and σ m, respectively, a value based on the rupture strength as σ B, and a value of more than 0 and less than 1.0 as x. ) SELECTED DRAWING: Figure 2

The utility model relates to a kind of metal composite material high-frequency fatigue test device, including support frame, testing device, protective cover and fixing device, testing device is installed on the support frame, the testing device is used to further test the tensile fatigue strength of metal by constantly increasing the force of stretching;The protective cover is installed on the testing device outside;The fixing device is installed on the testing device, and the fixing device is used to fix the metal to be tested.By the closed transmission chain of motor-reducer-screw integrated in test support, cooperate with the symmetrical limiting rod in displacement groove and displacement block limiting hole, the loading axis and the sample center line always keep high-precision coaxial, avoid eccentric error;Motor support supports reducer independently, suppresses bending deformation and resonance, improves long-term stability;Fixing device realizes sample trace eccentricity compensation, quick plug-in clamping and double-groove limiting positioning with the laminated structure of fixed block-adjusting disc-clamping block-mounting block, and different size samples can be replaced by a person.

The invention discloses a stud tensile fatigue test fixture and an assembly method, and relates to the technical field of test fixtures, the stud tensile fatigue test fixture comprises a first fixture and a second fixture which are symmetrically arranged at the two ends of a test bolt, the second fixture and the first fixture each comprise a fixture body, and the bottom of each fixture body is penetrated by the test bolt; a centering assembly is arranged between the test bolt and the clamp body; a fixing assembly is arranged at the end, penetrating through the clamp body, of the testing bolt. By adopting the stud tensile fatigue test fixture and the assembly method, automatic centering of the test bolt and the fixture can be realized, and the accuracy of a test result is improved.

The invention discloses a high-tensile fatigue-resistant adhesive tape material and a preparation method thereof. The core of the high-tensile fatigue-resistant adhesive tape material is to construct a dynamic ionic bond and bio-based coordination bond dual-crosslinking adhesive layer system. The adhesive layer is prepared by taking modified polylactic acid-cellulose nanocrystals as a bio-based matrix, matching with an ionic liquid modifier, introducing modified tea polyphenol and zinc acetate to form a bio-based coordination bond according to a molar ratio of 1: 3-1: 5 through solvent-free melt blending. The bio-based content of the adhesive tape is 50%-70%, the tensile strength is 15-18 MPa, the self-repairing efficiency is 85%-95% at the room temperature for 10-15 min, the 50% strain cycle fatigue resistance frequency is 10000-15000, the problem that the strength and self-repairing of an existing bio-based adhesive cannot be achieved at the same time is solved, and the adhesive tape is suitable for medical and flexible electronic scenes.

The invention discloses a spot welding cross-shaped structural member tensile fatigue test tool, which comprises a first adapter plate and a second adapter plate, five groups of first angle adjusting holes and second angle adjusting holes are respectively arranged on the first adapter plate and the second adapter plate at 0-degree, 30-degree, 45-degree, 60-degree and 90-degree positions, and the adjusting holes at the corresponding positions are combined in pairs for use. The spot welding device is used for spot welding rotation of the cross-shaped structural part at the positions of 0 degree, 30 degrees, 45 degrees, 60 degrees and 90 degrees. The first adapter plate is detachably connected with the first structural part connecting support through a first angle adjusting hole, and the second adapter plate is detachably connected with the second structural part connecting support through a second angle adjusting hole. The two longitudinal ends of the spot welding cross-shaped structural part are in threaded connection with the first structural part connecting support through bolts, and the two transverse ends of the spot welding cross-shaped structural part are in threaded connection with the second structural part connecting support through bolts. The clamping device has the technical effects of being flexible in angle adjustment, stable and reliable in clamping, high in adaptability, high in efficiency and high in safety.

The present application relates to the field of metal composite plate explosion welding, and provides a sample, a tool and a method for Z-direction fatigue test of an explosion composite joint, the sample comprising at least a top layer and a bottom layer, and the sample comprising at least one interface, the sample comprising: a circumferential boss part composed of an upper part of the top layer; a central column part arranged below the circumferential boss part, the central column part comprising at least a lower part of the top layer and the bottom layer; a tapered transition part arranged between the circumferential boss part and the central column part; an upper central through hole opened downward from the top of the sample and extending to below the interface to be tested by more than 1mm; and a lower central through hole in communication with the upper central through hole. The sample for Z-direction fatigue test of the explosion composite joint, one, controls the fatigue failure surface at the interface, and realizes accurate determination of the Z-direction fatigue performance of the explosion composite joint; two, does not easily cause interface fracture during installation; and three, can satisfy tensile-tensile fatigue, tensile-compressive fatigue and compressive-compressive fatigue tests.

The utility model discloses an indirect tensile fatigue test clamp. The indirect tensile fatigue test fixture comprises a base for supporting and placing a to-be-tested piece; a guide post is arranged on the base; the measuring table is sleeved on the guide column and moves up and down along the guide column; an opening penetrating up and down is formed in the measuring table, limiting guide rails are arranged on two opposite sides in the opening, and a displacement sensor adjusting structure is arranged on the measuring table above the opening; the pressing block is arranged on the guide column in a sleeving manner, and the pressing block is driven by external force to downwards apply pressure to the to-be-tested piece along the guide column; in the testing process, the displacement sensor adjusting structure makes contact with the to-be-tested piece in the direction perpendicular to the pressure of the pressing block and senses the displacement change of the to-be-tested piece in the direction. The indirect tensile fatigue test clamp has the functions of displacement sensor fixing and test piece guiding, the problems that a traditional displacement sensor fixed to a test piece is tedious in operation and inaccurate in data acquisition are solved, and the test piece can be conveniently guided to be damaged in the loading process.

The application discloses a method for predicting the fatigue fracture times of wind turbine blade composite materials, comprising the following steps: preparing a plurality of wind turbine blade composite material samples, each sample being prepared with two parallel test samples; taking one parallel test sample of each sample to perform a creep performance test under preset test conditions; taking another parallel test sample of each sample to perform a fatigue performance test; fitting the relationship between the creep strain and the fatigue fracture times; for the wind turbine blade composite material to be tested, performing a creep performance test under the same test conditions to obtain the creep strain, and according to the obtained relationship, obtaining the predicted fatigue fracture times of the wind turbine blade composite material. The method can complete the fatigue performance test and evaluation in a short time, establish a linear correlation model of creep and fatigue, calculate the fatigue fracture data by testing the creep strain data, and experimental results show that the theoretical calculation data is very close to the data obtained by the tensile fatigue performance test.

The invention discloses a seamless steel tube for a high-strength steering pull rod and a manufacturing method of the seamless steel tube. The seamless steel tube comprises the following components in percentage by weight: 0.12-0.35% of C; 0.1 to 1.0 percent of Si; 0.8 to 1.8 percent of Mn; 0.05 to 0.6 percent of Ni; 0.2 to 0.6 percent of Cr; 0.05 to 0.6 percent of Mo; 0.015% to 0.060% of Al; 0.02 to 0.25 percent of V; 0.015%-0.35% of Nb; the steel comprises the following components in percentage by weight: 0.2-0.8% of Ti, 0.015-0.1% of N, less than or equal to 0.025% of P, less than or equal to 0.015% of S and the balance of Fe and other inevitable impurities, and the elements also need to meet the condition that Ti / N is more than or equal to 2 and less than 0.6 < = (Mn + Cr) / 10 (V + Nb) < = 1.4. The tensile strength of the obtained seamless steel pipe is larger than or equal to 900 MPa, the yield strength is larger than or equal to 750 MPa, the ductility is larger than or equal to 30%, the-60 DEG C low-temperature impact energy is larger than or equal to 100 J, and the number of times of tensile fatigue resistance of cyclic tensile stress between 100 MPa and 500 MPa is larger than or equal to 1 million.

The utility model belongs to the field of test fixture detection, and particularly relates to a fixing fixture for a tensile fatigue test of a conical engineering plastic retainer, which comprises a clamping connecting plate, a large-end fixing baffle plate, a small-end fixing baffle plate, a rotatable pulling plate and a rotatable limiting block, the large-end fixing baffle and the small-end fixing baffle are fixedly connected to the clamping connecting plate, and the large-end fixing baffle abuts against the end face of the large end of the conical engineering plastic retainer and is attached to the end face of the large end. The small-end fixing baffle plate is propped against the outer diameter surface of the small end of the conical engineering plastic retainer and is attached to the outer diameter surface of the small end; the rotatable pulling plate is assembled in the holder window hole and hinged to the clamping connecting plate, and the rotatable limiting block is hinged to the rotatable pulling plate and attached to the holder window beam in parallel. The fixture can be used for fixedly clamping the conical engineering plastic retainer, simulating the state and the performance of the retainer in the use process of a bearing, and completing an anti-fatigue test. Interference of other assemblies is avoided, and performance measurement work is completed.

The invention discloses a reinforced filament composite screen printing plate according to regional stress demand difference and a processing method thereof, and relates to the field of composite screen printing plates, the technical scheme is as follows: the reinforced filament composite screen printing plate comprises a bottom layer, a middle composite layer and a top layer, the composite screen printing plate is provided with a plurality of hollow openings, a plurality of reinforced filaments penetrating through the hollow openings are arranged in the middle composite layer, and the top layer is arranged in the middle composite layer. A high-tensile fatigue demand area, a high-extrusion rigidity demand area and a structural balance demand area are formed on the composite screen plate corresponding to the width size of the hollow opening; the arrangement density or strength of the reinforcing wires in the high tensile fatigue demand area, the high anti-extrusion rigidity demand area and the structural balance demand area is increased along with the increase of the width size of the hollowed-out opening. The invention aims to provide the reinforced filament composite screen printing plate according to the regional stress demand difference and the processing method thereof.

The invention relates to the field of metal composite plate explosive welding, and provides a sample, a tool and a method for Z-direction fatigue testing of an explosive composite joint, the sample at least comprises a top layer and a tail layer, the sample at least comprises an interface, and the sample comprises a circumferential boss part formed by the upper part of the top layer; the central cylinder part is arranged below the circumferential boss part, and the central cylinder part at least comprises a lower part of a top layer and a tail layer; the conical transition part is arranged between the circumferential boss part and the central cylinder part; the upper central through hole is formed downwards from the top of the sample and extends to a position which is larger than 1mm below an interface to be tested; and the lower central through hole is communicated with the upper central through hole. According to the Z-direction fatigue test sample for the explosive composite joint, firstly, a fatigue failure surface is controlled at an interface, so that the accurate judgment of the Z-direction fatigue performance of the explosive composite joint is realized; interface fracture is not prone to being caused in the installation process; and 3, tension-tension fatigue, tension-compression fatigue and compression-compression fatigue tests can be met.