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.

Methods of detecting pipeline weakening are described herein. The methods include creating a pressure wave in a fluid flowing in a pipeline using an input transducer located at a first position along the pipeline; measuring the pressure wave using an output transducer positioned at a second position along the pipeline that is spaced from the first position, and generating an output signal based on the pressure wave; analyzing the output signal to determine a stiffness of a sidewall of the pipeline positioned between the input transducer and output transducer; and determining if the sidewall includes a defect based on the stiffness of the sidewall, including analyzing a frequency response of the output signal to detect the defect.

A method for evaluating the delayed fracture characteristics of a metal material. The method including placing a solution-retaining material impregnated with a solution containing a chloride and having a pH of 3.5 or more on a stress loading part of the metal material, and maintaining a state in which the solution-retaining material is held at a deliquescence humidity of the chloride to thereby corrode the stress loading part.

The present invention discloses a bending test apparatus and method for a flexible sheet material. The apparatus comprises a mounting table and further comprises a clamping unit and a bending shaft unit. The clamping unit comprises a clamping part. The bending shaft unit comprises a bending shaft extending in a Z-axis direction. The bending shaft has an arc-shaped sidewall for abutting against a flexible sheet material at an end thereof away from the clamping part. The clamping part moves relative to the bending shaft in a Y-axis direction. The present invention has the following advantage: During a test, a flexible sheet material is bent with a lower external strain, has a wide adjustment curvature range, and the structure is optimized.

The present invention discloses a bending test apparatus and method for a flexible sheet material. The apparatus comprises a mounting table and further comprises a clamping unit and a bending shaft unit. The clamping unit comprises a clamping part. The bending shaft unit comprises a bending shaft extending in a Z-axis direction. The bending shaft has an arc-shaped sidewall for abutting against a flexible sheet material at an end thereof away from the clamping part. The clamping part moves relative to the bending shaft in a Y-axis direction. The present invention has the following advantage: During a test, a flexible sheet material is bent with a lower external strain, has a wide adjustment curvature range, and the structure is optimized.

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.

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 marine climate environment-bending load collaborative acceleration test method is provided, including conducting a static bending load loading test in an outdoor marine climate environment, conducting an alternate cycle of a dynamic bending load loading test in the outdoor marine climate environment and a test in the outdoor marine climate environment, and conducting an alternate cycle of the dynamic bending load loading test and the static bending load loading test in the outdoor marine climate environment. In the present disclosure, an acceleration rate of the marine climate environment-bending load collaborative acceleration test reaches over 8 times that of the test in the outdoor marine climate environment by taking the maximum bending force as an evaluation index, which may achieve a change from a static test to a static and dynamic combined test for examining and evaluating the environmental adaptability of the metal material.

A marine climate environment-bending load collaborative acceleration test method is provided, including conducting a static bending load loading test in an outdoor marine climate environment, conducting an alternate cycle of a dynamic bending load loading test in the outdoor marine climate environment and a test in the outdoor marine climate environment, and conducting an alternate cycle of the dynamic bending load loading test and the static bending load loading test in the outdoor marine climate environment. In the present disclosure, an acceleration rate of the marine climate environment-bending load collaborative acceleration test reaches over 8 times that of the test in the outdoor marine climate environment by taking the maximum bending force as an evaluation index, which may achieve a change from a static test to a static and dynamic combined test for examining and evaluating the environmental adaptability of the metal material.

A method for identifying prestress force in single-span or multi-span PCI girder-bridges is provided. The method includes non-destructive steps for obtaining a set of parameters of the PCI girder-bridge under investigation, and combines various analyses to identify the change of prestress force. Therefore, the losses of prestress force are tracked and predicted. The method does not cause structural damages along the PCI girder-bridge, and the cost of the identification is significantly decreased.