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.

A test system includes subsystems for application to a test sample of a range of conditions that might be encountered in an actual application. Conditions may include the presence of particular fluid environments, temperatures, pressures, and mechanical loads including tensile and bending loads. The system is particularly suited for elongated samples such as tubular products used in oil and gas applications, though a range of samples may be tested.

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.

Bend test apparatus (100) for a hydraulic hose (200), the apparatus (100) comprising a main rack (10), at least one sliding rail (11) extending in a longitudinal direction (L) and a carriage (13) which is slidable on the sliding rail (11) in the longitudinal direction (L) and which can be displaced by an actuator (20), wherein the apparatus (100) further comprises a first fixture (1) that is rigidly attached to the main rack (10) to retain a first end (201) of the hydraulic hose (200) and a second fixture (2) that is rigidly attached to the carriage (13) to retain a second end (201) of the hydraulic hose (200), and wherein the apparatus (100) comprises a load cell (30) that is attached between the carriage (13) and the actuator (20) so as to detect a force (F) which is applied via the actuator (20) onto the carriage (13) and thereby onto the hydraulic hose (200) in the longitudinal direction (L).

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.

There are provided a method for predicting a springback amount and a method for bending a deformed reinforcing bar including: supplying the deformed reinforcing bar bending the supplied deformed reinforcing bar, and subsequently measuring a first bending angle in a state of releasing a bending force on the deformed reinforcing bar; further bending the reinforcing bar from which the bending force has been released, and subsequently measuring a second bending angle in a state of releasing the bending force; and predicting a relationship between the bending angle and the springback amount by using the measurement results after executing the further bending once or a plurality of times, in which the bending angle is greater for subsequent steps.

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 an edge face 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 edge face.

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.

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.