CN-121994598-A - Stress loading test device in extreme high-low temperature cycle test

CN121994598ACN 121994598 ACN121994598 ACN 121994598ACN-121994598-A

Abstract

The invention relates to the technical field of stress loading tests, in particular to a stress loading test device in an extreme high-low temperature cyclic test, which comprises a supporting frame, a clamping frame and a load-retaining device, wherein the supporting frame is made of invar, the low thermal expansion coefficient and the excellent dimensional stability of the supporting frame ensure the stability of a structure of the device in an extreme high-low temperature environment ranging from minus 180 ℃ to minus 180 ℃, the problem of uneven stress distribution caused by expansion and contraction is avoided, in addition, two fixing rods and the setting of a stretching end head are arranged on a stretching base, the locking mode of a first nut and a second nut is limited in opposite directions, the long-term retention of the stress of a test piece is realized, the performance study under a long-time service environment is facilitated, the stress distribution uniformity of the test piece in the test process is ensured through accurate loading and locking design, and the test result has higher reliability and repeatability.

Inventors

CHANG YIPENG
CHEN HAIJUN
SUN JIE
YANG XUEQIN
WEI LUMING

Assignees

苏州实验室

Dates

Publication Date: 20260508
Application Date: 20260225

Claims (10)

1. The stress loading test device in the extreme high-low temperature cycle test is characterized by comprising a supporting frame, a clamping frame and a load-retaining device; the support frame comprises a frame top and support columns, wherein two frame tops are arranged and are respectively and fixedly arranged at two ends of the support columns; the clamping frame comprises a test piece chuck, a fixed base and a stretching base, and the fixed base is fixedly connected to one of the frame tops; the stretching base is movably arranged on the other frame top, the distance between the stretching base and the fixed base can be changed, the test piece clamping head is provided with two clamping heads, the test piece clamping head is fixedly arranged on the stretching base and the fixing base and used for clamping the end part of a test piece; The load protection device comprises a fixed end, a stretching end and a locking assembly, wherein the fixed end is fixedly connected with the fixed base, the stretching end is connected with the stretching base, the stretching end penetrates through the frame top and extends outwards, the end part of the stretching end extending to the outside of the frame top is a clamping end, the fixed end can be fixed on an external tensile testing machine, the clamping end can be applied with load by the external tensile testing machine, and the locking assembly is used for locking the clamping end on the frame top.
2. The device for testing stress loading in an extreme high and low temperature cyclic test according to claim 1, wherein the support columns are hollow rectangular invar steel, two support columns are arranged, and the two support columns are distributed in parallel and at intervals between the two frame tops.
3. The device for stress loading test in extreme high and low temperature cyclic test according to claim 1, wherein the frame top is of a II-type invar double-layer structure, the frame top is of a hollow structure, and the frame top is connected with the support column through welding.
4. The device for testing stress loading in an extreme high and low temperature cycle test according to claim 3, wherein the frame top is internally provided with a stabilizing block, the stabilizing block is made of invar steel material and is fixedly arranged in the middle of the frame top.
5. The device for testing stress loading in the extreme high and low temperature cycle test according to claim 1, wherein the test piece clamping head is provided with a clamping slit, the end part of the test piece can be inserted into the clamping slit, and the test piece clamping head is provided with a fixing bolt for fixing the end part of the test piece in the clamping slit.
6. The device for testing stress loading in the extreme high and low temperature cycle test according to claim 1, wherein the stretching base is fixedly provided with a positioning pin, and the positioning pin penetrates through the top of the frame in a sliding manner.
7. The device for testing stress loading in an extreme high and low temperature cycle test according to claim 4, wherein the fixed end is fixedly connected with the fixed base, the fixed end penetrates through the top of the frame and extends outwards, the fixed end penetrates through the stabilizing block, and one end of the fixed end extending to the outside of the top of the frame can be fixed on the external tensile testing machine.
8. The device for testing stress loading in the extreme high and low temperature cycle test according to claim 1, wherein the locking assembly comprises two fixing rods, the fixing rods are fixed on the stretching base, the two fixing rods are distributed on two sides of the stretching end head, the fixing rods penetrate through the frame top in a sliding mode, first thread grooves are formed in the outer side walls of the fixing rods, and first nuts can be screwed on the fixing rods extending to the outer portion of the frame top.
9. The device for testing stress loading in the extreme high and low temperature cycle test according to claim 8, wherein a second thread groove is formed in the outer side wall of the clamping end of the stretching end, and a second nut can be screwed onto the second thread groove.
10. The apparatus of claim 9, wherein the first nut is locked in a direction opposite to the second nut to form a bi-directional locking mechanism.

Description

Stress loading test device in extreme high-low temperature cycle test Technical Field The invention relates to the technical field of stress loading tests, in particular to a stress loading test device in an extreme high-low temperature cyclic test. Background In the aerospace field, the development of aerospace vehicle tank materials is gradually changed from traditional alloy materials to carbon fiber composite materials, which is a necessary trend for realizing lightweight design. However, the storage tanks of the space vehicles often face extreme environmental tests in the actual service process, including complex mechanical loading conditions and extreme temperature environments such as ultralow temperature or high temperature, and particularly under high-temperature low-temperature thermal fatigue conditions, the composite materials can cause significant performance degradation due to thermal-force coupling. In order to study the performance changes of carbon fiber composites in extreme environments, it is often necessary to apply a stable stress loading to the material during high and low temperature cycling tests. The conventional test method is usually to test by mechanical test equipment matched with a high-low temperature test environment box, but the equipment has a plurality of limitations. Firstly, the existing equipment is difficult to adapt to the requirement of an extremely low-temperature environment (such as-180 ℃) so that the test result cannot accurately reflect the performance of the material under the real service condition. Secondly, the structure of current device is comparatively fixed usually, and complex operation is difficult to realize the batch test of material to research efficiency has been restricted. In addition, the prior art has insufficient stress retention capability in a long-time low-temperature service environment, and cannot meet the requirement of long-term stability test of the composite material. Therefore, the realization of stable stress loading of the composite material sample piece under the extremely high and low temperature environment becomes a great technical difficulty of the current research, and is also a key point for pushing the practical application of the composite material storage tank material. The development of a test device capable of performing high and low temperature cyclic test within the range of-180 ℃ to 180 ℃ and keeping stable stress loading is of great significance in revealing failure mechanisms of composite materials in extreme environments and evaluating residual performances of the composite materials. Disclosure of Invention The invention provides a stress loading test device in an extreme high-low temperature cyclic test, which aims to solve the problem that the existing stress loading test device cannot perform the stress loading cyclic test on a composite material at high and low temperatures. The stress loading test device in the extreme high-low temperature cyclic test adopts the following technical scheme: the stress loading test device in the extreme high-low temperature cycle test comprises a supporting frame, a clamping frame and a load-protecting device; The support frame comprises a frame top and a support column, two frame tops are respectively and fixedly arranged at two ends of the support column, the clamping frame comprises a test piece chuck, a fixed base and a stretching base, the fixed base is fixedly connected to one frame top, the stretching base is movably arranged on the other frame top, the distance between the stretching base and the fixed base can be changed, the two test piece chucks are fixedly arranged on the stretching base and the fixed base, one test piece chuck is fixedly arranged on the two fixed bases and used for clamping the end part of a test piece, the holding device comprises a fixed end head, a stretching end head and a locking assembly, the fixed end head is fixedly connected with the fixed base, the stretching end head is connected with the stretching base, the end part of the stretching end head extending to the outer part of the frame top is a clamping end, the fixed end head can be fixed on an external stretching testing machine, the clamping end head can be applied with load by the external stretching testing machine, and the locking assembly is used for locking the clamping end head on the frame top. Further, the support columns are hollow rectangular invar steel, two support columns are arranged, and the two support columns are distributed in parallel at intervals between the two frame tops. Further, the frame top is of a II-type invar double-layer structure, the frame top is of a hollow structure, and the frame top is connected with the support column through welding. Further, the inside stabilization piece that is provided with in frame top, the stabilization piece is made by invar material is solid, stabilization piece fixed mounting in the inside in the middle of the frame top