The present disclosure provides a dynamic true triaxial electromagnetic Hopkinson bar system and testing method, the method including: firstly, before applying a static prestress and an impact load, recording and storing complete ultrasonic signals in the directions X, Y, and Z without application of the static prestress and the impact load; secondly, applying the static prestress; thirdly, recording and storing complete ultrasonic signals in the directions X, Y, and Z under the static prestress; fourthly, applying the impact load, and utilizing an triaxial and six-directional synchronous-coordinated-control electromagnetic loading system to apply a dynamic impact load to a test specimen; and fifthly, after completing the dynamic impact loading test, recording and storing once again complete ultrasonic signals in the directions X, Y, and Z without releasing the static prestress after application of the static prestress and the dynamic impact load.

The present disclosure provides a dynamic true triaxial electromagnetic Hopkinson bar system and testing method, the method including: firstly, before applying a static prestress and an impact load, recording and storing complete ultrasonic signals in the directions X, Y, and Z without application of the static prestress and the impact load; secondly, applying the static prestress; thirdly, recording and storing complete ultrasonic signals in the directions X, Y, and Z under the static prestress; fourthly, applying the impact load, and utilizing an triaxial and six-directional synchronous-coordinated-control electromagnetic loading system to apply a dynamic impact load to a test specimen; and fifthly, after completing the dynamic impact loading test, recording and storing once again complete ultrasonic signals in the directions X, Y, and Z without releasing the static prestress after application of the static prestress and the dynamic impact load.

A method for evaluating long-term durability of a resin for piping is provided. Unlike the conventional FNCT evaluation method requiring a long period of time, the method disclosed herein is capable of predicting long-term durability of a resin for piping in a short time, by a simple calculation using a content of tie molecules, an entanglement molecular weight (M.sub.e) and a content of ultrahigh molecular weight components. In addition, the olefinic polymer is configured to have a predetermined relationship in relation to the content of tie molecules, the entanglement molecular weight (M.sub.e) and the content of ultrahigh molecular weight components, whereby the polymer of the present application can be used in the manufacture of a heating pipe requiring excellent long-term durability.

The present disclosure discloses a reciprocating rock fracture friction-seepage characteristic test device and method. The test device includes an X-axis shear system, a Y-axis stress loading system, a Z-axis stress loading system, a servo oil source system, 5 a pore pressure loading system, and a host. The X-axis shear system includes an X-axis EDC controller, an upper shear box, a lower shear box, an X-axis left hydraulic cylinder, an X-axis right hydraulic cylinder, an X-axis left pressure head, an X-axis right pressure head, an X-axis left pressure sensor, an X-axis right pressure sensor, an X-axis displacement sensor, and an X-axis 10 displacement sensor. The pore pressure loading system includes an air cylinder, a pressure gauge, a pressure reducing valve, a fluid inlet pipeline, a fluid outlet pipeline, and a flowmeter.

The present disclosure discloses a reciprocating rock fracture friction-seepage characteristic test device and method. The test device includes an X-axis shear system, a Y-axis stress loading system, a Z-axis stress loading system, a servo oil source system, 5 a pore pressure loading system, and a host. The X-axis shear system includes an X-axis EDC controller, an upper shear box, a lower shear box, an X-axis left hydraulic cylinder, an X-axis right hydraulic cylinder, an X-axis left pressure head, an X-axis right pressure head, an X-axis left pressure sensor, an X-axis right pressure sensor, an X-axis displacement sensor, and an X-axis 10 displacement sensor. The pore pressure loading system includes an air cylinder, a pressure gauge, a pressure reducing valve, a fluid inlet pipeline, a fluid outlet pipeline, and a flowmeter.

A polymer suitable for use in a thin film hinge (living hinge) comprising from about 0.1 to about 5 weight % of a C.sub.4-8 comonomer and the balance ethylene, said composition having a density as determined according to ASTM D 792 from about 0.945 to about 0.965 g/cm.sup.3; a melt index as determined according to ASTM D1238 (2.16 kg/190° C.) from about 10 to about 20 g/10 min; a weight average molecular weight (Mw) from about 45,000 to about 55,000 g/mol; a polydispersity from about 2.5 to about 3.1 and when molded into a strip having a length of about 13 cm and gross thickness from about 50 to about 70 mil (about 1 to about 2 mm) and completely bent over end to end four times to create a thinned region or crease having a thickness from about 15 to about 30 mil (about 0.3 to about 0.7 mm) tested by bending and releasing the deformed thinned region of the strip through a radius of curvature from about 180 to about 190° about a rounded plate goes through not less than 500 cycles without breaking.

A polymer suitable for use in a thin film hinge (living hinge) comprising from about 0.1 to about 5 weight % of a C.sub.4-8 comonomer and the balance ethylene, said composition having a density as determined according to ASTM D 792 from about 0.945 to about 0.965 g/cm.sup.3; a melt index as determined according to ASTM D1238 (2.16 kg/190° C.) from about 10 to about 20 g/10 min; a weight average molecular weight (Mw) from about 45,000 to about 55,000 g/mol; a polydispersity from about 2.5 to about 3.1 and when molded into a strip having a length of about 13 cm and gross thickness from about 50 to about 70 mil (about 1 to about 2 mm) and completely bent over end to end four times to create a thinned region or crease having a thickness from about 15 to about 30 mil (about 0.3 to about 0.7 mm) tested by bending and releasing the deformed thinned region of the strip through a radius of curvature from about 180 to about 190° about a rounded plate goes through not less than 500 cycles without breaking.

An instrument and method for mechanical properties in situ testing of materials under a high temperature and complex mechanical loads are provided. The instrument includes: a support frame module used to provide a stable support and an effective vibration isolation for each functional module of the instrument; a high-frequency fatigue load applying module used to apply a high-frequency fatigue load on a tested sample; a static-dynamic mechanical load applying module used to apply a combination of static-dynamic tension/compression/bending loads on the tested sample; a high/low temperature applying module used to apply a variable temperature environment from a low temperature to a high temperature on the tested sample; and an in-situ monitoring module that may integrate a surface deformation damage measurement assembly, a three-dimensional strain measurement assembly, a microstructure measurement assembly, and an internal damage detection assembly according to a practical testing requirement.

A device for fatigue test includes a sample-laying part, a sample support, and a force-applying part. The sample-laying part is disposed on the sample support; and the force-applying part is disposed on the sample-laying part; the sample-laying part includes a substrate plate and at least two arms disposed on the substrate plate; the sample support includes a bed plate and at least four roller assemblies disposed on the bed plate; each roller assembly includes a roller, a roller support, and an adjusting bolt; the roller support is disposed on the bed plate; the roller is disposed on the roller support; the adjusting bolt is disposed between the roller and the roller support; and the sample support further includes at least one barrier, and both ends of the barrier are connected to two adjacent roller supports, respectively.

A device for fatigue test includes a sample-laying part, a sample support, and a force-applying part. The sample-laying part is disposed on the sample support; and the force-applying part is disposed on the sample-laying part; the sample-laying part includes a substrate plate and at least two arms disposed on the substrate plate; the sample support includes a bed plate and at least four roller assemblies disposed on the bed plate; each roller assembly includes a roller, a roller support, and an adjusting bolt; the roller support is disposed on the bed plate; the roller is disposed on the roller support; the adjusting bolt is disposed between the roller and the roller support; and the sample support further includes at least one barrier, and both ends of the barrier are connected to two adjacent roller supports, respectively.