Search results

This problem of crack closure becomes more serious in the case of back-wall cracks in thick-walled structures, especially in the welded regions, as the large scattering noise from the grain boundaries of the weld metals decreases the accuracy of the evaluation drastically.
Therefore, DCPD technique is realized to be capable of eliminating some of the major problems encountered in the ultrasonic testing of cracks, as it is practically free from the problem of crack closure as well as that of grain noises.
The accuracy as well as reliability of the developed measuring system has been verified through the evaluation of a number of 3-D back-wall cracks in 40mm-thick stainless steel plates.

Experimental procedures The ingots of Al7SiMg alloy (chemical composition: Si 6.69; Mg 0.37; Fe 0.29; Zn <0.01; Ti<0.01; balance Al; numbers as quoted by the producer in mass %) were melted in resistance furnace at 750 °C.
Mg3Sb2 will be crystallized at grain boundary prior to eutectic phases because of the high melting point.
As modifier for Al7SiMg alloy equal or over 0.20 wt. % Sb, some surplus Sb will precipitate at grain boundary in the form of compound Mg3Sb2.

In case of aggregates it depends on mineralogy and size of grain and can by specified by coefficient of thermal expansion or coefficient of thermal conductivity.
Even though the content of fine particles under 0.063 was 7.2%, the grains are very sharp and don’t contribute to improving the workability.
Volume 15/Number 1, March 1994

The size, the number and the distribution of these second phase particles have a great influence on the quality of aluminum foil.
A small amount of Mn can improve the corrosion resistance and weldability of the aluminum, Mg can improve its tensile strength, Ti and B are mainly added as grain refiner [6].
New combination of polishing and etching technique for revealing grain structure of an annealed aluminum (AA1235) alloy[J].

Table 4 Grain size distribution of aggregates [mass%] Sieve size[mm] <0.16 0.16 0.315 0.63 1.25 2.5 5.0 10 16 19 26.5 Fine 100.0 98.8 91.2 64.6 35.8 17.8 7.0 Coarse 99.6 99.5 97.9 58.9 21.9 0.0 High-range water-reducing admixture.
Table 5 presents the details of 10 different concrete mixture proportions, here the plain concrete (Number 1, Sign O) without mineral admixture was acted as reference concrete.
Table 6 Properties of fresh concrete Number Sign Slump[mm] Density[kgm-3] air content [%] 1 O 212 2400 1.24 2 A1B2 215 2390 0.95 3 A2B1 223 2380 0.97 4 A3 212 2380 0.94 5 B3 225 2370 0.95 6 A2B2 223 2370 0.78 7 A1B3 215 2380 0.80 8 A3B1 217 2380 0.76 9 A4 230 2375 0.75 10 B4 232 2390 0.81 Strength of concrete specimens.
Table 7 Strength of concrete specimens Number Sign Flexure strength[MPa] Split tension strength[MPa] 7d 28d 90d 28d 1 O 4.35 5.87 6.19 2.70 2 A1B2 4.76 5.77 6.76 2.72 3 A2B1 4.33 5.29 5.89 2.89 4 A3 3.59 5.52 7.13 3.14 5 B3 4.92 6.39 7.19 3.78 6 A2B2 4.69 6.72 7.86 2.82 7 A1B3 4.74 6.41 7.38 3.53 8 A3B1 3.85 5.70 6.05 2.81 9 A4 3.50 4.98 6.24 3.33 10 B4 4.96 6.88 7.44 3.26 Flexure strength of concrete.
The cement dispersing mechanism makes available more cement grain surfaces to be accessible for the water, thus, early hydration is more complete [1,7].

Literature Review FSW produces a dynamically recrystallized grain structure in the nugget, which has reached near-solutionizing temperatures, before being "quenched" by the surrounding material back to room temperature at the completion of the weld.
PWAA can also be used to modify the distribution of precipitates in the final joint to influence strength and corrosion properties, and has been demonstrated to be beneficial for a number of alloy and temper combinations.
In addition, the propensity for abnormal grain growth, reported by many researchers in the nugget and TMAZ, discourages the use of solution heat treatment following FSW as a primary mode of improving its resistance to corrosion.
The two PWAA treatments performed comparably to or better than the parent material in FCP for both crack length vs. number of cycles and da/dN vs.
No. of Cycles Al-7075-T73 (0.125" thick) 0.30 0.50 0.70 0.90 1.10 1.30 1.50 1,000 10,000 100,000 1,000,000 Number of Cycles Crack Length (in) 7075-T73_100 hrs@225F 7075_325_2hrs 7075_325_4Hrs 7075-Parent-01 7075-Parent-02 7075-Parent-03 Naturally Aged da/dN vs.

D= kλβcosθ (4) where D is the grain size of the crystal, λ is the wavelength of X-ray radiation (nm), K is the Scherer constant (0.9), β is FWHM (radians), and θ is the Bragg angle (radians).
C-S-H gel hydrates the permanent cement of C3S by filling the spaces between the tricalcium grains.
This is because CuONP can reduce the number of nano-sized pores in C-S-H while also strengthening the microstructure of the MTA/CuO cement composite.
The wave number at 1026 cm-1 is the Si-O-Cu absorption peak derived from the shift in the SiO2 absorption peak [30].
Acknowledgments The authors gratefully acknowledge the Ministry of Education, Culture, Research and Technology, Republic of Indonesia, through a grant of Regular Fundamental Research (PFR), contract number 3152/UN1/DITLIT/DitLit/PT.01.03/2023 for financial support.

Lomonodov observed twinning in steel ferrite grains in the depth of the material for more than 0.5mm below the surface after a laser pulse [3].
In 2008 the ultra-compact LPwC system (1.5m long and 30kg) was developed; this represents a significant milestone versus versatility, accessibility as well as reliability due to smaller number of parts reducing the operational and maintenance cost of the system.
Although the fatigue initiation resistance of an integral structure is considerably increased because the reduction of the number of fasteners (i.e. stress concentration points) the fail safe and damage tolerance behavior is reduced.
Large number of tests was carried out in Oxford University where a biaxial fretting fatigue test rig was developed for this specific configuration [36].
Kuroki, “Laser processing for reducing core loss of grain oriented silicon steel”, J. of Applied Physics, Vol. 53 (1982), 2410

This will limit the number of suppliers and set focus on manufacturing method rather than an overall reliable system including the mechanical components and their joining.
In general one would expect higher yield-strength and higher tensile strength for forged components due to the reduced grain size [4] .
The FCC-structure is known for having a less steep increase in yield strength with decreasing grain size [6].
The number of tensile specimens was 21 for the “A”-series, and 7 for each of the other series in both bar dimensions.
The gasket ring dimensions were adopted from ASME B16.20 standard [18] and are valid for a groove number of R24.

(3) (4) (5) (6) (7) A, E0 δvc, δvt hj E90 Aeq δh nh G Bi t Ksf,i nsf,i δnsx,i δnsy,i p Kp-f np cross section and Young modulus parallel to grain of studs; vertical displacements at the two opposite ends of the shear wall due to the compression of the base timber joist and to the deformation of the hold-down connections subjected to tension, respectively; depth of the cross section of the base joist; Young modulus perpendicular to grain of the base timber joist; stud equivalent cross section; vertical displacement of a single hold-down connection stressed by a unitary vertical force; number of hold-down subjected to tension; sheathing shear modulus; width of the i-th segment of the shear wall; global thickness of the sheathing; stiffness of the single base shear connection; number of base shear connections in the i-th segment; horizontal displacement due to the deformation of nails between sheathing and
The various displacement contributions may be evaluated through the following relationships: (9) with (10) (11) with (12) (13) nn,h Kser,h1 Es l2 l3 l4 l5 l7 s ϕk ns Lh4 Lh5, Ah5 number of nails in the hold down; slip modulus per shear plane per fastener (if a wooden-based panel is interposed between the hold-down and the timber studs, it is necessary to consider both the slip modulus of the steel-to-panel connection and that of the panel-to-frame, by summing them in parallel); Young modulus of the steel; distance of the first nail row from the base; distance of the first nail row from the ribs weld; the distance of the first nail row from ribs; hold-down width; distance between the axis of the threaded rod and the vertical plate of the hold down; hold-down thickness; hole diameter at hold-down base; number of overlapping steel sheets forming the hold-down base; equivalent length of the hold-down