Deep-Sea Tensile Impact Testing With Pretensioned Hopkinson Bars
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Solution Overview
Problem
Existing Hopkinson bar devices are limited in their ability to perform both static and dynamic mechanical tests, particularly under high-pressure environments, failing to simulate deep-sea conditions necessary for the testing of materials used in underwater exploration equipment.
Innovation Solution
A pretension and tensile impact test apparatus integrating a pre-tensioning device, Hopkinson bar device, seawater pressure simulation, and acquisition control unit, capable of performing static and dynamic tensile tests under simulated deep-sea pressures up to 140 MPa, with features like pre-loading and creep tests.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional Hopkinson bar devices are used for dynamic mechanical testing, then dynamic tensile and compressive properties can be tested, but static mechanical tests such as static tensile, creep, and fracture tests cannot be performed simultaneously
Solution Approach 1:
The patent combines a pre-tensioning device for static mechanical tests with a Hopkinson bar device for dynamic mechanical tests into an integrated testing system. The pre-tensioning device includes a loading frame and loading mechanism that can apply static loads, while the Hopkinson bar component enables dynamic impact testing. This merging allows both static and dynamic tests to be performed on the same material sample without requiring separate testing equipment.
Solution Approach 2:
The integrated device is designed to perform multiple functions: static tensile testing, creep testing, fracture testing, and dynamic impact testing. The loading frame and Hopkinson bar system work together to provide a universal testing platform that can accommodate different test types through configurable loading mechanisms and sample mounting arrangements.
2Stress or pressure
If existing Hopkinson bar devices operate under normal pressure or with pressure-confining devices (≤50 MPa), then testing under moderate pressure is possible, but high-pressure environment testing especially ultra high-pressure environment (>50 MPa) cannot be achieved
Solution Approach 1:
The patent implements a nested pressure simulation system where an inner pressure chamber is placed within an outer pressure chamber. The inner chamber contains the test sample and Hopkinson bar components, while the outer chamber provides additional pressure containment. This nested structure enables the system to achieve ultra-high pressure conditions (>50 MPa) by stacking pressure containment levels, with each chamber contributing to the overall pressure resistance.
Solution Approach 2:
The patent introduces a pressure transmission medium (such as liquid or gas) as an intermediary to transfer and distribute pressure uniformly to the test sample and internal components. This mediator allows the external pressure applied to the outer chamber to be transmitted effectively to the inner chamber and test specimen, enabling accurate high-pressure testing while isolating the sensitive measurement components from direct mechanical stress.
3Temperature
If exploration equipment reaches certain depth with increasing cable length and seawater pressure, then deep-sea exploration capability is improved, but the dynamic behavior of the cable becomes extremely complex requiring comprehensive mechanical property testing
Solution Approach 1:
The patent uses a nested pressure chamber structure where an inner pressure-resistant chamber is placed within an outer pressure chamber. This nested configuration creates isolated environments that can simulate deep-sea pressure conditions while protecting the external laboratory environment. The inner chamber contains the test sample and testing mechanisms, allowing accurate simulation of deep-sea mechanical properties without requiring the entire testing system to be submerged.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables comprehensive mechanical property testing of materials under high-strain rates and deep-sea pressures, including creep and fracture tests, providing essential data for material evaluation in ultra-high pressure conditions.
Implementation Method 1
the air compressing device comprises an air cylinder, an end cover and an impact piston; two ends of the air cylinder are each provided with the end cover; the impact piston is in clearance fit with the air cylinder
Implementation Method 2
the pre-tensioning device, the input rod, the air compressing device, the seawater pressure simulation device, the test sample and the output rod are arranged in sequence on the same axis; one end of the input rod is connected to the pre-tensioning device
Implementation Method 3
the seawater pressure simulation device; the test sample is provided inside the pressure seawater device
Data Source
AI summary
A pre-tension and tensile impact test apparatus capable of simulating a full-sea-depth environment includes a pre-tensioning device, a Hopkinson bar device, a seawater pressure simulation device, a power source group and an acquisition control unit. The Hopkinson bar device includes an input rod, an air compressing device, a test sample and an output rod. The pre-tensioning device, the input rod, the air compressing device, the seawater pressure simulation device, the test sample and the output rod are successively arranged on the same axis. The air compressing device includes an air cylinder, an end cover and an impact piston. Two ends of the air cylinder are each provided with the end cover. The impact piston and the air cylinder are in clearance fit. The input rod is coaxially connected to the impact piston. Two ends of the input rod each extend out of the end cover.