1 edition of Strain dependent damping characteristics of a high damping manganese-copper alloy found in the catalog.
Strain dependent damping characteristics of a high damping manganese-copper alloy
Dwight D. Dew
|Other titles||NPS 69-86-007.|
|Statement||by Dwight D. Dew|
|The Physical Object|
|Pagination||143 p. :|
|Number of Pages||143|
Two types of high-damping metals were chosen for the study: a series of die cast zinc-aluminum alloys that exhibit predominantly amplitude-independent, thermally activated damping mechanisms and a manganese-copper (Mn-Cu)-based alloy casting that exhibits pronounced amplitude-dependent damping together with thermally activated damping. Fatigue properties of manganese-copper damping alloys (OCoLC) Material Type: Government publication, National government publication: Document Type: Book: All Authors / Contributors: J W Jensen; A E Schwaneke; D F Walsh; United States. Bureau of Mines.
Zn−Al alloys are found to exhibit relatively high damping capacity in many literatures [1,6−8]. Aluminum alloys especially series (Al−Zn−Mg−Cu) have been used in many fields [9−11], but their damping capacities need to be improved. Therefore, Al−Zn−Mg−Cu alloy matrix composites reinforced with Zn−Al alloy . Discontinuously reinforced high damping MMCs Discontinuously reinforced MMCs have attracted considerable attention because of their feasibility for mass production, promising mechanical properties and potential high damping capacity. In particular, discontinuously reinforced aluminum alloy MMCs provide high damping and low density.
The influence of Y on the microstructure and damping capacity of AZ91D based alloys was investigated by optical microscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and dynamic mechanical analysis. The results show that, with increasing Y content, the grain size of α-Mg matrix decreases tremendously and the distribution of β-Mg17Al12 phase is. Fig. 1 Constitutional Diagram of Manganese Copper Alloys as Determined by Ishiwara. 6. Fig. 2 Lattice Parameters of Manganese-Copper Alloys. 6. Fig. 3 Constitutional Diagram of Manganese Copper Alloys Taken From a Compilation by Hansen 8 Fig. 4. Effect of Quenching Temperature on the Electrical Resistance of Mangan-ese-Copper Alloys 30 Fig. 5.
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This banner text can have markup. web; books; video; audio; software; images; Toggle navigation. Approved for Public release; distribution is unlimitedThis paper presents the studies on measurement techniques developed for the determination of strain-dependent damping characteristics of materials in an air environment.
The material is a high damping manganese-copper alloy called : Dwight D. Dew. Electron-microscope, X-ray, and neutron-diffraction techniques have been used to identify those microstructural features thought to be responsible for the high damping capacity of manganese-copper.
Only those compositions that are tetragonal have a high damping by: That ageing is necessary to produce useful damping capacities in the manganese-copper alloys is known.
A detailed correlation between damping and ageing variables has, therefore, been established, so providing a basis for the specification of material for particular operating conditions of stress and by: A specific damping capacity of 26 % was recorded for Sonoston, a commercial high-damping manganese/copper alloy.
This was exceeded only by a coarse flake graphite cast iron and annealed nickel (magnetomechanical). The damping of cast irons is due to the shape of the graphite inclusions rather than to the quantity of free graphite in the steel Cited by: M alloy is a MnCu based high damping alloy that shows high damping capacity and the superior workability.
In the present work, the microstructure and damping behavior of the alloy in different. Effects of solute atomic characteristics on the strain amplitude independent damping and the strain amplitude dependent damping of the alloys are discussed below.
As shown in Fig. 5, the Mg-1at%Sn alloy exhibits the highest low strain amplitude damping, followed by the Mg-1at%Al alloy.
In contrast to the strain-dependent damping, ε c becomes lower with reducing impurities in the alloys, as seen in Table 2. Tensile properties It is very interesting to investigate the tensile properties of the as-extruded specimens since reducing impurity content causes a great enhancement of damping values in the as-extruded state.
The viscous damping force is dependent on the frequency of oscillation. The equation of motion is therefore Structures under harmonic forcing experience stress that leads the strain by a constant angle. For a harmonic strain, where ν is the forcing frequency.
The induced stress is Manganese copper alloy Rubber-natural Table 4. Material Damping Ratios (Bare Structure) System Viscous Damping Ratio ξ Reinforced Concrete Small Stress Intensity (uncracked) Medium Stress Intensity (fully cracked) High Stress Intensity (fully cracked but no yielding of reinforcement) to to to Prestressed Concrete (uncracked) to Influences of static strain on the damping capacity in Mn-based M and Fe-6AI alloys were studied with the forced flexural oscillation method by using a dynamic mechanical analyzer (DMA).
High strain rate rolling (HRSS) of a ZK60 magnesium alloy at °C with a strain rate from 5 s−1 to 25 s−1 was used to research the effect of the rate on the mechanical properties and damping capacity of the ZK60 alloy.
The results show that as the strain rate increases, the tensile strength decreases from MPa at 25 s−1 to MPa at 5 s−1. development of high-damping metals (hidamets) and high-damping metal-matrix composites (M M Cs).
MMCs become particularly attractive in weight-critical applications when the matrix and reinforcement phases are combined to provide high-damping and low-density characteristics. Strain Dependent Damping Characteristics of a High Damping Manganese-Copper Alloy by Dwight D.
Dew Lieutenant Commander, United States Navy B.A., University of South Florida, Submitted in partial fulfillment of the requirements for the degrees of M.S.
IN MECHANICAL ENGINEERING and MECHANICAL ENGINEER from the NAVAL POSTGRADUATE SCHOOL. The composites are characterised by a high damping capacity. Fig. 3 shows the mechanical loss angle as a function of the temperature in both composites, the spectrum for an industrial alloy (AZ63) is displayed as a comparison.
The damping capacity level is lower in C / Mg than in SiC / Mg, but largely higher than in the industrial alloy. alloys, Mn–Cu damping alloys are well known to have the high damping capacity, accompanied with the satisfactory mechanical properties, such as strength and ductility.1,2) Historically the development of high damping alloys was conducted based on Mn–Cu binary alloy.
SONOSTON alloy (Mn–Cu–Al–Fe–Nimass%) was the ﬁrst. Manganese-copper binary alloys ranging from 50 to 80 wt pct Mn, both cast (1)4 and powder-metallurgy consolidated (I), exhibit SDC's in the range 20 to 25 pct at a stress of 5, psi.
In addition to high damping capacity, these alloys have useful mechanical properties comparable to those of mild steel. Static strains in the vicinity of ×10 −4 caused the formation of a damping peak, which accelerated the increase of the damping capacity in the M alloy, but softened the decrease of the damping capacity in the Fe–6Al alloy.
A significant reduction of the damping capacity appeared at static strains above ×10 −4 in both high. High-Damping Metals (HIDAMETS) are the physical metallurgist’s answer to unwanted noise and vibrations. However, the characterization of the damping properties of metals and alloys is neither simple nor straightforward.
This is mainly because the damping mechanisms involved depend upon the stress-induced movement of defects in the metal in question which, in turn, implies a dependence. Lin H C, Wu S K and Yeh M T Damping Characteristics of TiNi Shape Memory Alloys Metallurgical Transactions A 24 –94 CrossRef Google Scholar  Wu K, Yang F, Pu Z and Shi J The Effect of Strain Rate on Detwinning and Superelastic Behavior of NiTi Shape Memory Alloys.
structure, which provides high damping due to the high density of its dislocations. Table III shows the values of grain and noise levels of standard and advanced steels. A steel condition is normalized.
As can be seen, the grain size ranges from 1 to 8 points on the G scale. AM1 and AM2 alloys are presented as a .Measurement of the strain-dependent damping of metals in axial vibration R D Adams and A L Percival Measurement of the flexural damping capacity and dynamic Young's modulus of metals and reinforced plastics R D Adams and D G C Bacon Damping of ferromagnetic materials at direct stress levels below the fatigue limit R D Adams.The high-damping state at roan temperature in SONOSTON is very amplitude dependent, and the results are similar to those observed in ferromagnetic high-damping alloys.
Besides the high-damping peak close to room tempera- ture, there is a major relaxation peak in SONOSTON and in the binary fi/Cu alloy at * '~. The ~~ peak is probably a.