Search results

Introduction Roof abscission layer is the unified external behavior of comprehensive action of ground stress, the mechanical properties of surrounding rock, rock structure, and anchor strengthening coefficient, roadway section and other factors, it is an integrated index which can predict the roadway stability and get all the attention at home and abroad in recent years.
Main Factors Influencing Roof Abscission Layer (1) In-situ stress In-situ stress is the basic reason for deformation and failure of roadway surrounding rock, with the increase of stress, elastic displacement, plastic displacement and dilatancy displacement of surrounding rock is a growing trend
(2) Rock mechanical behaviors Rock mechanical behaviors have important influence on roadway stability of surrounding rock, the higher mechanical parameters of surrounding rock, the smaller the deformation of roadway and the greater the roadway stability
(6) Size of chain pillars Size of chain pillars determines influence degree of the residual abutment pressure of adjacent goaf, which is the important influence factor of roof abscission layer.
(3) The critical value of roof abscission layer is affected by many factors.

The bias instability is affected by 1/f noise.
However, the drift property is quite inferior in front of traditional mechanical sensors.
However, more researches are waiting to find the dominant factors that determine the bias instability when referring to the specific blocks of systems.
The closed loop scale factor with DFA is 2.5V/g, and the loop with MFA is about 15V/g.
Micro Electro Mechanical Systems (MEMS), 2013 IEEE 26th International Conference, 20-24 Jan. 2013, 29-32

Picking-up and clearing parts are the key device of the important work parts for the line chili harvesting machine, which directly affect the performance of the harvesting machine.
As a "red industry" in Xinjiang, and currently or artificial picking harvest, harvest season when busy season, labor is very nervous, and there is a labor intensity and low efficiency, cost is high, which seriously restrict factors chili industrialization process.
The early stage of the material properties of chili and planting mode research: picking on the current chili breadth of planting pattern design; Roller diameter according to chili plant height and mechanical speed; the spiral spring tooth arrangement, spacing according to the properties of material chili fruits and decide that favor picking chili.
Spring tooth use spring steel wire around and become, for spring tooth is rigid, picking on the damage for larger, chili reduce the damage rate, increase mechanical properties, in spring steel wire surface with buffer role of suit rubber.
Reduce the impurity rate, increase mechanical properties.

This paper analyzes the factors, which causes the no-linear of the ultrasonic in the processing system, and the reasons of the ultrasonic reflection and transmission at the contact interface according to the wave theory.
For a long time, due to the test conditions and other factors, many scholars did not focus on the contact interface effects on the system dynamics, or limited to empirical understanding.
The properties of the material at the contact interface is inconsistent so discontinuous propagation occurs at the interface.
The contact interface pretension and the connection mode often leads to instability of the ultrasonic energy output, which producing a great effect on the ultrasonic vibration, thereby affecting the effect of ultrasonic machining.
Fig.5 Trends of the amplitude and preload Fig. 6 Test site Fig.7 Vibrational spectrum shape and dimensional array map when preload 0.046N Fig.8 Vibrational spectrum shape and dimensional array map when preload 0.058N Conclusions Ultrasonic propagation in the material is affected by the physical properties of the material, this paper only discussed the reason that ultrasonic may occur reflection, transmission in the contact interface in ultrasonic machineing, discussed its propagation in the contact interface, through the test established the relationship between piezoelectric ceramics preload and ultrasonic vibration effects.

Other studies have focused on the mechanical properties of these mortars [24]; [3]; [25]; [9]; [20].
The following properties of mortars specimens were determined: compressive and flexural strength and water absorption by capillarity.
In the following results is shown the hardened properties of mortars containing kaolin wastes as pozzolan and inert material.
F., Kaolinitic calcined clays: Factors affecting its performance as pozzolans.
[36] AMBROISE, J.; MAXIMILIEN, S. e PERA, J., Properties of metakaolin blended cements.

On the basis of the study mentioned above, the formation mechanism and influencing factors of the landslide are deeply analyzed.
On the basis of the study mentioned above, the formation mechanism and influencing factors of the landslide are deeply analyzed.
Formation Mechanism Analysis Influence Factors.
The sliding zone is softening by the water of reservoir and the mechanical strength is reduced.
The landslide stability is affected seriously under the Three Gorges reservoir operation, which will seriously endanger people's lives and property safety.

The addition of the extrusion process and/or the ECAP process in fabrication can be an option to improve its properties.
However, Mg weakness in terms of mechanical properties and degradation rates need to be improved.
Characterization of miniplate samples includes visual forms, a microstructure with an optical microscope (OM) and mechanical properties.
Mechanical properties test was carried out through a three-point bending test (ASTM E290) with test speed of 10mm/min.
Besides the density factor, the grain size of the miniplate affected the bending test results.

Stress-based performances of four commercially-available dental implant systems are evaluated in detail, demonstrating that implant and bone stability is strongly affected by implant-abutment connection structure as well as by a number of geometrical parameters.
A key factor for the success or failure of a dental implant is the manner in which stresses are transferred to the surrounding bone [1].
And 0.5 mm of element size is utilized as the meshing requirement for all the FE models Materials Properties.
Mechanical properties of the materials are shown in Table 1.
Table 1 Isotropic materials properties used in the study Material Young's modulus(GPa) Poisson ratio (v) Yield strength (MPa) Titanium CP 117 0.30 462 Ti-6Al-4V 110 0.32 800 Gold alloy 100 0.30 565.4 Table 2 Elastic coefficients for cortical and cancellous bone used in the study Ex(GPa) Ey(GPa) Ez(GPa) Gxy(GPa) Gyz(GPa) Gxz(GPa) v xy vyz vxz Cortical bone 12.6 12.6 19.4 4.85 5.7 5.7 0.3 0.39 0.39 Cancellous bone 1.148 0.21 1.148 0.068 0.068 0.434 0.055 0.055 0.322 Results and Discussion Maximum von-Mises (EQV) stresses that occurred at the bone, implant, abutment and screw of the four FE models for the loading condition are presented in Table 3 and the stress distribution are shown in Fig.3.

Materials properties.
The two factors were very usefully in the simulation progress.
Materials properties used in finite element simulation were summarized in the Table 1.
Materials properties were used in finite element analyses Material properties Cr-Mo-Cu alloy cast iron GCr15steel ball L/W=2,5 L/W=10 Elastic modulus,(GPa) 120 103 210 Density,(g/cm3) 7.4 7.1 7.8 Poisson ratio 0.3 0.3 0.3 Shear stress,(GPa) 0.29 0.29 -- Tangent modulus,(GPa) 80 80 -- Friction coefficient 0.6 0.5 -- Wear rate,(mm3/(m·N)) 5.5×10-5 1.6×10-4 -- Results and discussion Shear stress and plastic strain.
The change of shear stress which was related to the propagation of subsurface micro crack was an important factor to affect the wear progress, so basing on the shear stress the third strength theory was used to analyze the wear progress.

Effect of indenter geometries on material properties: A Finite Element simulation J.J.
These techniques can be used not only to obtain and to interpret the hardness of the material but also to provide information about the near surface mechanical properties, deformation behaviour of bulk solids and properties of coating films.
In particular, unloading curves from the indentation data contain information related to the material properties.
This may be attributed to differences in mesh refinement near the tip zone or other factors relating to the difference between the indenter geometries.
Despite having identical material properties and identical maximum applied displacements, there are differences between the loading-unloading curves obtained from FE simulations.