Papers by Keyword: High-Strength

Abstract: Unidirectional composite structures are increasingly utilized in structural design due to their excellent compressive strength. The present study provides an evaluation of the fatigue performance of materials commonly used in hip prostheses such as Ti-6Al-4V, Co-Cr alloys, UHMWPE, and a silicon matrix composite reinforced with unidirectional carbon fibers in three different fiber volume fractions. Using Bergmann's loading factors, stress calculations were conducted for an 80 kg individual. The Goodman criterion and S-N curves were applied to assess fatigue life. Results show the unidirectional composite with 70% fiber volume fraction has the highest fatigue resistance, making it most suitable for high-stress applications. In contrast, Ti-6Al-4V and Co-Cr alloys showed moderate performance, while UHMWPE was found to be suitable for low-stress applications. These results underscore the necessity of selecting the ideal composition to maximize durability and fatigue resistance in essential mechanical applications. This finding suggests a promising alternative for improving the design and performance of femoral neck implants. This suggests a promising alternative for improving the design and performance of femoral neck implants.

Abstract: Hydrogen technology can be one key for a transition to sustainable energy necessary to achieve climate targets and limit global warming to 1.5 °C since the beginning of the industrial revolution. Hydrogen as a CO₂ neutral energy carrier must replace fossil fuels from the existing natural gas grid and infrastructure to enable an environmentally friendly and circular economy in future societies. Batteries and e-fuels are practicable technologies for short term and quantitatively limited energy provision, with disadvantages including raw material demands and technologically complex transformation cycles. Utilizing advanced power-to-gas concepts, hydrogen will not only be most efficient technology in energy storage, but also allows adaption and reuse of existing energy transportation infrastructure.To provide volatile hydrogen gas in the required flow and energy densities, advanced compression technology needs to be developed inspired by conventional gas compression systems. Reciprocating piston compressors are developed for high-pressure hydrogen applications, providing high pressure levels and flow rates. Compression equipment must be designed for non-lubricated dry-running conditions, as high gas purity standards of hydrogen do not allow for oil-based lubricants to be introduced into the process gas. High-strength carbon fiber reinforced composites are developed as piston and packing ring materials to withstand extreme pressure differences under harsh thermo-mechanically loaded operation conditions.Promising candidates with high strength and wear resistance in the form of PPS-polymers, are developed with PTFE solid lubricants and different carbon fiber fractions to combine high strength, with low friction and wear, improve pressure operation range, and limit down times of hydrogen piston compressors. The current work describes tribological testing of advanced PPS-polymers with 10 to 30 wt.% carbon fibers in a high-velocity tribometer under hydrogen gas atmosphere. Supporting thermo-mechanical tests give new insights in deformation mechanisms of fiber reinforced polymer composites and allow conclusions on their applicability for hydrogen compression.

Abstract: The steel ingots of high-strength structural steel HG785D were produced by using a special water-cooled copper ingot mold. It analyzed the reason of the slab to achieve rapid solidification and shrinkage reducing with the simulation by using AnyCasting software. The difference properties between 100mm and 240mm steel plate with the same components were studied. The results show that properties are better with the increasing of the compression ratio, the times of TMCP and the reduction. The properties of 240mm steel plate with different composition were studied under the same heat treatment condition. Niobium, vanadium and titanium are in favor of the mechanical properties, but have little effect on the plasticity of structural steel. It should increase the harden ability of the alloy elements to improve mechanical properties of the steel HG785D.

Abstract: The paper demonstrates that indirect testing performed with thermal microscopy facilities can be used successfully to study the properties of heat-resistant added metal.

Abstract: By ANSYS finite element analysis we study the impact-span moment and deflection of high strength recycled concrete beam in state of initial cracking and yield with different water-cement ratio and recycled coarse aggregate replacement rate. The results showed that: 1With the increase of water-cement ratio and recycled coarse aggregate replacement rate, the deflection is on the rise. 2With the increase of recycled coarse aggregate replacement rate, the yield moment has a slight upward trend. And with the increase of water-cement ratio and recycled coarse aggregate replacement rate, the span deflection at the state of yield has a growing trend.

Abstract: High-strength and high-conductivity copper alloy is a kind of structural function materials, which has excellent comprehensive mechanical and physical properties. The strengthening methods of copper alloy are summarized. The basic requirements of high-strength and high-conductivity copper alloy is established. The application of the materials is described, including lead frame materials, electrified contact wires materials, electrode Materials. Meanwhile, the alumina dispersion strengthened copper alloy is introduced. The internal oxidation process, structure, dispersoid and anti-intenerate properties have also been analysis in detail. Finally, the development direction of this material is put forward.

Abstract: Based on the horizontaldisplacements and loads of column at top end deduced according to sectionalbalanceable conditions at yield of high-strength frame columns, the lateralmaximum loads of column at top end calculated according to the Chinese currentconcrete code and involved regressive formulas, the resilience model ofhigh-strength concrete frame columns were established. The main results show:the resilience models of high-strength concrete frame columns proposed in thispaper consider influenced multi-facts and conveniently applied to engineering.

Abstract: This paper proposes the use of high-strength continuous compound spiral hoop in avoiding various weaknesses, such as steel wastes from conventional hooped reinforcement, overcrowding of hoop at reinforcement areas, and difficulties in concrete vibration and construction. It also analyzes the advantages of high-strength continuous compound spiral hoop in construction processes, operational key points, and quality control. It shows that the high-strength continuous compound spiral hoop can prevent various weaknesses in conventional hooped reinforcement, minimize the consumption of steel and improve work efficiency.

Abstract: The ultra-low carbon high strength weathering steel was trial manufactured. By Optical micrographs observation, scanning electronic microscope (SEM), transmission electronic microscope (TEM), accelerated corrosion test, the corrosion resistant performance of test steel and CortenB steel were studied. The results showed that yield strength, tensile strength, elongation and -40 °C impact energy of test steel reached 510MPa, 600MPa, 22% and 115J, respectively. Corrosion resistance of test steel was superior to that of CortenB. The microstructure of ferrite and bainite, quickly forming adhesive dense rust layers to improve the corrosion resistance of test steel.

Abstract: The development trend for diagnostics is reducing the diameter of coaxial signal cables that comprise the probe cable. The thinner super-fine coaxial cable which is offering superior electronic and mechanical properties, such as 75 %IACS(International Annealed Copper Standard, electrical conductivity) and 700 ~ 800 MPa in tensile strength has to be developed. Cu-Ag based system is one of the most promising systems for high strength and high conductivity Cu alloys. In order to find the optimum conditions to obtain Cu-Ag-Zr-Co alloy with high strength and high electrical conductivity, the aging characteristics including work hardening of micro-Vickers hardness, tensile strength and electrical conductivity of this alloy were systematically measured at room temperature. Also the influence of aging treatment was investigated by transmission electron microscopy(TEM) and scanning electron microscopy(SEM) in this study. The aging treatment for precipitation was divided into two steps and carried out at various time and at different temperature and the multi-step aging treatment coupled with cold rolling was proposed for realizing Cu-Ag-Zr-Co alloys with high strength and high electrical conductivity. The electrical conductivity was improved from 31 %IACS to 91 %IACS remarkably and the tensile strength was increased from 230Mpa to 690Mpa greatly by an optimization of alloy composition and manufacturing process including aging.