A bending applying device includes three mandrels and applies bending to an optical fiber by winding the optical fiber onto the mandrels. The mandrels are alternately arranged at predetermined intervals such that outer circumferences of adjacent mandrels in a longitudinal direction of the optical fiber face each other in a non-contact manner. A diameter of the optical fiber is D, a radius of the mandrel is r, an interval between the adjacent mandrels in the first direction is 2r + d, a direction orthogonal to the first direction is a second direction, an interval between the adjacent mandrels in the second direction is s, and an angle θ between the second direction and a common internal tangent of the adjacent mandrels is 0 degrees or more and 45 degrees or less, and the formed angle θ satisfies following formula.

[00001]$\sqrt{\left(d+D+4r\right)\left(d-D\right)+s^2}=2\left(r+\frac{D}{2}\right)\tan \theta +\frac{s}{\cos \theta }$

The present invention discloses a landslide experimental device for remotely controlling and simulating a constant seepage flow and weight load and an experimental method thereof in centrifuge test. The landslide experimental device includes a model box, a landslide device, a near-constant water flow control box, remote control devices and a water outlet pipe. The landslide device comprises a landslide model, a load balancing device, a weight storage device, an angle control panel and a tension bar. The remote control devices are arranged at the control box water outlet, at the control box water inlet, on the tension bar, on telescoping control sensors and on the weight storage device, respectively. With the present invention, the influences on the stability of landslide model with different landslide angles under the condition of the seepage flow and weight load can be simulated.

In a material testing machine including a load actuator including a shaft configured to make a linear motion, and configured to apply a load to a test piece through the linear motion of the shaft, the load actuator includes a bearing configured to support the shaft, and the bearing serves as an air bearing.

A device and a method for testing tensile resistance of multiple-row grouped pillars in an inclined goaf are provided. The bottoms of stands of the device are connected with a testing machine base, and the tops of the stands of the device are connected with a transverse frame; an upper slideable clamping seat and a lower slideable clamping seat are semi-cylindrical blocks, multiple lower loading jaws that are positioned to have a same central line are arranged on the lower slideable clamping seat, each of the lower loading jaws is opposite to a corresponding one of the upper loading jaws, the lower loading jaws are welded to the lower slideable clamping sea to test the tensile resistance of samples together; the upper part of the upper slideable clamping seat is connected with an upper pressure disk, and the lower slideable clamping seat is connected with a lower pressure disk.

The vertical counterforce loading device includes a concrete support member, four transfer components, four connection components, a vertical force transmission component and a load test soil layer. The concrete support member is formed by pouring and concreting below the load test soil layer. The four transfer components are divided into two groups to be symmetrically and parallelly anchored in the concrete support member. The vertical force transmission component includes a load plate, a jack, a primary beam and a secondary beam arranged in sequence from bottom to top. The load plate is installed on the load test soil layer. Two secondary beams are connected crosswise to both ends of the primary beam, where end portions of the secondary beams are respectively connected to second ends of the connection components through reinforcement components. The device can improve work efficiency, reduce construction costs and improve safety.

A test apparatus comprises a probe movably mounted relative to a carrier. The probe comprises an end portion with a surface area of about 5 mm.sup.2 or less. The test apparatus can be used in methods of determining a crush strength of an edge of a substrate. Methods can comprise aligning the probe with a test location of the substrate at a predetermined angle relative to a probe axis. Methods can further comprise applying a mechanical force to the test location with the probe in the direction of the probe axis. Also, methods can comprise increasing the mechanical force applied by the probe until the substrate cracks or a predefined force applied by the probe is reached. Based on the mechanical force applied by the probe, a crush strength of an edge can be determined.

A device is for detecting compaction and shear strength characteristics of an asphalt mixture during construction compaction. The device includes a fixed frame and a detection system. The detection system includes a display, a control panel, a test claw, an electric motor, a lift switch, a torque sensor and a temperature sensor. The control panel includes a power switch for controlling the electric motor and a speed regulator for controlling a rotation speed of the test claw. An output end of the electric motor is connected to an input end of the torque sensor, and an output end of the torque sensor is connected to an input end of the test claw. An output end of the test claw is provided with a claw-shaped blade. The claw-shaped blade is provided therein with the temperature sensor.

A device for testing overall anchorage performance of a basalt fiber reinforced plastic (BFRP) anchor cable includes an anchor cable anchoring system and a data acquisition system. The anchor cable anchoring system includes a test bed, BFRP arranged over the test bed, and a distributed optical fiber bonded to a surface of the BFRP, the test bed being provided with an anchoring section at one end and an outer anchoring section at the other end, the anchoring section anchors one end of the BFRP, and the outer anchoring section anchors the other end of the BFRP. The data acquisition system includes a modem and a grating connected to two ends of the distributed optical fiber in series, and a center hole jack and a dynamometer arranged between the outer anchoring section and an end of the test bed, and the BFRP penetrates the center hole jack and the dynamometer.

A fracture toughness testing machine of the invention makes it possible to evaluate fracture toughness of a specimen in pure mode such that the effect of thermal residual stresses is removed, when the stresses are present in the specimen obtained by bonding dissimilar materials. The testing machine includes: testing-load applying means for applying a predetermined testing load to the specimen, in which the stresses are present; and cancelling-load applying means for applying a cancelling load to the specimen to cancel the stresses therein. The cancelling-load applying means includes: a pressing-force applying portion that applies a pressing force to the specimen as the canceling load; and a pressing-force determining portion that determines magnitude of the force. The pressing-force determining portion calculates the magnitude of the force using pre-stored equations so that an energy release rate related to in-plane shear mode crack deformation becomes zero.

According to the metal foil fatigue test system and metal foil fatigue test method of the present invention, the fatigue degree and lifespan of the metal foil may be easily predicted by injecting gas into the tube of a roll structure and discharging the gas to simulate charge/discharge of the electrode assembly.