Increase In Displacement Rate Research Articles

Effects of water saturation and loading rate on direct shear tests of andesite

For estimating the long-term stability of underground framework, it is vital to learn the mechanical and rheological characteristics of rock in multiple water saturation conditions. However, the majority of previous studies explored the rheological properties of rock in air-dried and water saturated conditions, as well as the water effects on compressive and tensile strengths. In this study, andesite was subjected to direct shear tests under five water saturation conditions, which were controlled by varying the wetting and drying time. The tests were conducted at alternating displacement rates under three vertical stresses. The results reveal that the shear strength decreases exponentially as water saturation increases, and that the increase in shear strength with a tenfold increase in displacement rate is nearly constant for each of the vertical stresses. Based on the findings of the shear tests in this study and the compression and tension tests in previous studies, the influences of both water saturation and loading rate on the Hoek-Brown failure criterion for the andesite was examined. These results indicate that the brittleness index of the andesite, which is defined as the ratio of uniaxial compressive strength to tensile strength, is independent of both water saturation and loading rate and that the influences of the water saturation dependence and the loading rate dependence of the failure criterion can be converted between each other.

Experimental Study of Water Displacement Rates on Remaining Oil Distribution and Oil Recovery in 2D Pore Network Model

An amount of oil remains in oil reservoirs even at the high water-cut stage of produced liquid from oil wells. To reveal the mechanism of displacement rates to affect the remaining oil in pore scales, a two-dimensional (2D) glass etching pore network model and real-time visual system were set up to observe the characteristics of oil distribution from water flooding and study the influence of displacement rates on oil recovery. It was found that the geometry of remaining oil in the pore network is diverse and dynamically changed at the high water-cut stage. Three geometric representative parameters were defined for the classification of five types of remaining oil (contiguous, branching, film, dropwise, bar columnar type), and controlling mechanisms for each type of remaining oil were analyzed. The experimental results show that the remaining oil saturation decreases from 21.2% to 6.5% when water injection rates increase from 0.05 to 0.5 mL/min. The increase in displacement rate improves the displacement efficiency of four types of remaining oil in the range of 55.00% to 93.67% except for dropwise type. The experimental data also indicate that the reduction in continuous residual oil and branched residual oil mainly contributes to the improvement of oil recovery of the whole network model. With the increase in displacement rate (from 0.05 to 0.1, 0.2, 0.3, 0.4, and 0.5 mL/min), the areas of five types of representative local residual oil reduce step by step. This research validates that the increase in water flooding rate in porous media leads to reduction in oil saturation, and it will improve oil recovery in oil reservoirs by enhancing water injection rates.

Effect of Test Temperature and Displacement Rate on Semicircular Bend Test

Asphalt concrete behavior under load is heavily influenced by displacement rate and temperature. It was the objective of this study to quantify the effect of these two parameters on asphalt mix performance under a semicircular bend (SCB) test. The ultimate goal of this study was to find the most suitable combination of displacement rate and temperature for the SCB test to be conducted in the northeast region of the United States. In addition, the effects of air void, binder content, and binder stiffness in the SCB test were investigated. SCB tests were performed at a temperature range from 10°C to 30°C, and displacement rates ranging from 1 to 50 mm/min. Material variables included air voids (4% versus 7%), binder contents (design versus design + 0.5%), and binder stiffness (three different grades). Characterization parameters from the test included fracture energy (FE), flexibility index (FI), peak load (PL), stiffness index (SI), and prepeak fracture energy (PPFE). The data were analyzed statistically to evaluate the sensitivity of characterization parameters to material variables under different displacement rates and test temperatures. The results indicated that FE, PL, and SI all increase with the increase of displacement rate and decrease with the increase of test temperature, while FI exhibited an opposite trend. The previously used PPFE demonstrated poor sensitivity to material variables regardless of displacement rate and test temperature. FE, FI, and SI show higher sensitivity to material changes compared with PPFE. Among all response parameters, PL proved the most sensitive to material variables irrespective of test conditions. The effective temperature concept was used to determine a suitable fatigue test temperature for the northeast region. The level of sensitivity was not affected as a result of changing the test temperature from 25°C to the effective temperature. Based on the test results, a displacement rate between 5 and 20 mm/min is recommended for use with the SCB test.

Characterizing Afterslip and Ground Displacement Rate Increase Following the 2014 Iquique‐Pisagua Mw 8.1 Earthquake, Northern Chile

AbstractThe 2014 Iquique‐Pisagua Mw 8.1 earthquake ruptured only parts of the 1877 Northern Chile‐Southern Peru seismic gap. Here we present a comprehensive analysis of 152 continuous and campaign Global Positioning System time series that captured more than a decade of interseismic loading prior to the event and 2 years of afterslip. In high spatiotemporal resolution, our data document upper plate response not only at the coseismically affected latitudes but also at the adjacent Loa plate segment to the south. Using a combination of elastic and viscoelastic half‐space models of different stages of the seismic cycle, we found that the highly coupled, former seismic gap contains a narrow low coupling zone at 21°S latitude. Just after the 2014 earthquake, this zone acts as a barrier impeding afterslip to continue southward. Possible reasons for this impediment could involve crustal heterogeneities or coupling discontinuities at the plate interface. After 2 years, afterslip cumulates to a maximum of ~89 cm and becomes negligible. Global Positioning System observations south of the inferred seismotectonic barrier reveal a deformation rate increase in the second year after the event. Our slip models suggest that this could be caused by a downdip coupling increase, perhaps bringing the highly coupled southern Loa segment closer to failure. Taken together, our results reveal (1) the interaction between different areas undergoing stress release and stress buildup in a major seismic gap, (2) constraints for the temporal variation of coupling degree in different stages of the seismic cycle, and (3) the influence of large earthquakes at adjacent segments.

Correlating laboratory and full-scale reflective cracking tests for airfield pavements

Asphalt overlays minimize moisture infiltration and help in restoring the smoothness and structure of existing airfield concrete pavements, but due to reflective cracking, the new asphalt overlay often fails before achieving its design life. In airfields, the potential for reflective cracking presents a major challenge for rigid pavement rehabilitation involving asphalt overlays. To assist airport engineers and others concerned with the temperature-induced reflection cracks, several full-scale test pavements have been constructed, instrumented, and tested at the Federal Aviation Administration (FAA) National Airport Pavement Test Facility (NAPTF). The main objective of this study was to identify and develop correlations between full-scale and laboratory reflective cracking tests. A customized Overlay Tester (COT) and Cyclic Disc-Shaped Compact Tension (CDCT) Test were used evaluate the fracture and fatigue performance of hot mix asphalt (HMA) materials at low temperatures. The COT was conducted at the same conditions as the full-scale tests and test results were analyzed using several parameters. Temperature effect was pronounced in strain parameters (initial strain, failure strain, and strain at Nf(NLC)). Further fatigue parameters (Nf(crack) and Nf(NLC)) indicated a swifter deterioration of HMA mixture at a higher displacement (cooling) rate. Fracture parameter (Gfini) was found to decrease with the increase of displacement rate due to the brittleness of HMA at low temperatures as excepted. A two-term exponential function from the CDCT tests demonstrated the fracture behavior of HMA under cyclic loading. The released energy rate factor (R2) correlated well with the fatigue life. Finally, a set of shift factors were derived between the full-scale, OT, and CDCT tests. Valuable data obtained from this study provides immediate support to the future FAA reflective cracking research.

Impact Tensile Properties of Notched Titanium Alloy Bolt for Fairing Separation of Launch Vehicle

The payload fairing in Japan is fixed by a lot of notched bolts. These notched bolts were fractured by axial impact tensile using the explosive devices to separate the fairing. In this case, the stress waves and the oscillations propagate, which may seriously damage the satellites. In this study, the impact deformation and the fracture behavior of notched titanium alloy bolt was investigated using a split Hopkinson pressure bar method. The notched bolt specimen was made of commercial Ti-6Al-4V alloy. The maximum load value was increased with increasing the displacement rate. It can be said that the strain rate dependence of strength for Ti-6Al-4V alloy appeared. From the observation of fracture surface using a scanning electron microscope, compared with the quasi-static test, it was clear that the irregularities of the fractured surface at the impact tensile test became rough. Therefore, it was found that the brittle fracture was mainly observed due to the increase in displacement rate, which may mean that the mode of fracture changes from the transgranular to the intergranular. It was surmised that this change of fracture mode was caused by the high strain rate due to stress concentration of the notched part.

Stable crack growth in composite laminates under various stiffness of the loading system

The work is devoted to experimental study of stable and unstable crack growth processes in composite materials. The eccentric tension tests of the compact specimens of glass-epoxy composite laminates in conditions of various stiffness of the loading system were carried out. Different measurement techniques of crack opening displacement were used in work. During the analysis of results of a tension test of compact specimens with crack, descending sections of the loading curves were considered by analogy with postcritical deformation stage, which could be found in test of smooth specimens of different materials. It is shown that behavior of composite specimens with crack under tension depends on the loading system parameters: crack grows process is stable when stiffness of the loading system is enough, crack opening displacement rate increase under reduction of stiffness of the loading system. This effect should be take into account during modeling and analyzing of fracture processes of composite materials, strength and survivability assessment of composite structures in real loading conditions.

Clay Creep and Displacements: Influence of Pore Fluid Composition

Time dependent shear displacements in clay soils under constant effective stresses can also be induced by changes in pore fluid composition. This paper presents the results of laboratory tests carried out on a sodium bentonite and on samples of the Varicoloured Clays formation outcropping east of Potenza, Southern Italian Apennines. The soils reconstituted with a 1M NaCl solution were submitted to shear tests under constant shear stresses in two different conditions: i) after shearing to the residual state, and ii) intact at various OCR. The applied shear stresses were lower than the residual strength of the materials reconstituted with the salt solution (residual friction angle, φ’r ≈ 15°) and higher than that obtained with distilled water (φ’r ≈ 5°). While exposed to 1M NaCl solution, the specimens didn’t experiment creep; on the contrary, exposure to distilled water made the displacement rate increase greatly. The decrease in pore ion concentration obliterated the over-consolidation effects.

Changes in bedrock channel morphology driven by displacement rate increase during normal fault interaction and linkage

AbstractWe attribute changes in the morphology of relay ramp channels (increased slope and decreased width) to variations in displacement rate on ramp‐adjacent normal faults. We map the faults and fluvial channels associated with four sites in different stages of fault interaction and linkage on the Volcanic Tableland, a Late Pleistocene ash‐flow tuff in east‐central California. Because these channels are inactive today, we estimate downstream changes in channel width and depth using HEC‐RAS, a one‐dimensional open channel flow model. Our results show that channel slope must be greater than about 0.05 before there are substantial decreases in width or substantial increases in depth. Displacement rate increases during interaction between en echelon segments results in the increases in channel slope and decreases in channel width. Moreover, our data show that these changes begin to occur during the very early stages of fault interaction, well before the fault geometry would indicate ongoing or imminent linkage.

Eruption forerunners from multiparameter monitoring and application for eruptions time predictability (Piton de la Fournaise)

Volcanic eruptions impact on societal risk, and volcanic hazard assessment is a necessary ingredient for decision‐makers. However, the prediction of volcanic eruptions remains challenging due to the complexity and the non‐linearity of volcanic processes. Identified forerunners such as increasing seismicity or deformation of the volcanic edifice prior to eruption are not deterministic. In this study, we use statistical methods to identify and discriminate precursory patterns to eruptions, on three sets of observables of Piton de la Fournaise volcano. We analyzed the short‐term (i.e. the inter‐eruptive period) time series of the seismicity rate, the deformation and the seismic velocity changes (deduced from seismic noise cross‐correlations) over the period 1999–2006, with two main goals. First, we characterize the average pre‐eruptive time patterns before 22 eruptions using superposed epoch analysis for the three observables. Using daily rate values, we resolve (1) a velocity change within 100–50 days from the eruptions onsets, then a plateau value up to eruption onset; (2) a power law increase in seismicity rate from noise level 15–10 days before eruption time; (3) an increase of displacement rate on the eruption day. These results support a three step mechanism leading to magma transfers toward the surface. Second we use pattern recognition techniques and the formalization of error diagrams to quantify the predictive power of each forerunner either as used independently or as combined to each other. We show that when seismicity rate alone performs the best prediction in the failure to predict versus alarm duration space, the combination of the displacement and seismicity data reduces the false alarm rate. We further propose a tool which explores the prediction results in order to optimize prediction strategy for decision‐makers, as a function of the risk value.

High Resolution Imaging of Unstable, Forced Imbibition in Berea Sandstone

An experimental investigation is presented of immiscible, high-mobility ratio forced imbibition in a representative linear homogeneous sandstone. Water floods with mobility ratios (from 1 to 155) at various water injection rates were conducted. Fine-scale (order mm3) in situ water saturation history was collected via X-ray computed tomography (CT). Three-dimensional images were constructed of stable displacement and the initiation and growth of unstable water fingers. Interestingly, viscous fingers do not lead the displacement front by significant distances, counter to experience in miscible systems. In this homogeneous porous medium, both water (displacing phase) injection rate and oil (displaced phase) viscosity have an obvious effect on the stability of the water front. As the oil viscosity and displacement rate increase, the water front becomes less stable. In addition, the so-called shock mobility ratio, as computed from steady-state relative permeability, is found to be predictive regarding displacement front stability. When the shock mobility ratio is greater than 1, the displacement is always unstable. Steady-state relative permeability, however, is found to be a function of viscosity ratio for unstable displacements.

Effect of Patient Age on the Radiographic Outcomes of Distal Radius Fractures Subject to Nonoperative Treatment

Our study assessed the radiographic outcomes of nonsurgically treated distal radius fractures of patients who were 18 to 44 years old (group 1), 45 to 64 years old (group 2), and 65 years old or older (group 3). All distal radius fractures seen in our emergency department from April 2002 to September 2004 that had nonsurgical management (either casting alone or closed reduction with immobilization) were considered for this study (n = 124; 50 casted, 74 closed reduced). Patients were further classified by age. Change in fracture alignment was assessed at the time of fracture union (approximately 8 weeks) and included measurements of angulation, articular gap/step-off, and radial shortening. When the fractures (n = 124) were evaluated at union, there was an overall secondary displacement rate of 64% (n = 79), with 42% in the group whose fractures were immobilized in a cast and 78% in the group whose fractures were treated by closed reduction and cast. There was an increase in displacement rate that was associated with increasing patient age. Among fractures that were only casted, there was no such age-matched increase in rates of secondary displacement. However, when considering those fractures that were subject to closed reduction (n = 74), rates of secondary displacement significantly increased with age (58% in group 1, 81% in group 2, and 89% in group 3; p = .03). Our study found that secondary displacement of distal radius fractures increased with increasing patient age, primarily among fractures subject to closed reduction. Older patients with these fractures require closer management after initial reduction, therefore allowing for better monitoring of expected subsequent fracture collapse. Further, given these high rates of secondary displacement after nonoperative treatment (58% to 89%), it is also important to consider that surgical treatment of these fractures may be necessary.

Footwall drainage evolution and scarp retreat in response to increasing fault displacement: Loreto fault, Baja California Sur, Mexico

Research Article| July 01, 2007 Footwall drainage evolution and scarp retreat in response to increasing fault displacement: Loreto fault, Baja California Sur, Mexico Estelle Mortimer; Estelle Mortimer 1Institut für Geowissenschaften, Universität Potsdam, Karl-Liebknecht-Strasse 25, Potsdam D-14476, Germany Search for other works by this author on: GSW Google Scholar Barbara Carrapa Barbara Carrapa 1Institut für Geowissenschaften, Universität Potsdam, Karl-Liebknecht-Strasse 25, Potsdam D-14476, Germany Search for other works by this author on: GSW Google Scholar Geology (2007) 35 (7): 651–654. https://doi.org/10.1130/G23690A.1 Article history received: 25 Jan 2007 rev-recd: 28 Feb 2007 accepted: 04 Mar 2007 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Estelle Mortimer, Barbara Carrapa; Footwall drainage evolution and scarp retreat in response to increasing fault displacement: Loreto fault, Baja California Sur, Mexico. Geology 2007;; 35 (7): 651–654. doi: https://doi.org/10.1130/G23690A.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract The displacement rate history of the Loreto fault, Gulf of California, is well documented; it is characterized by episodically accelerating displacement (10 k.y. frequency) superimposed upon a period of 200 k.y. of increasing fault displacement rate. A detailed conglomerate provenance analysis in the Loreto basin records the footwall unroofing history, which has been profoundly affected by increased fault displacement rate. Clast count data capture an immediate drainage response to a significant increase in slip rate, along with the occurrence and systematic increase in abundance of a new source rock type. Our data record an increase in the rate of incision and catchment expansion associated with this increase in displacement rate. A provenance signal from a shorter-term (100 k.y.) displacement rate increase has a 30–40 k.y. lag time. No change in provenance is recorded for high-frequency (10 k.y.) variations, which are filtered out by the system. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.

Testing environmentally assisted cracking of reactor materials using pneumatic servo-controlled fracture mechanics device

The degradation mechanism, known as stress corrosion cracking or environmentally assisted cracking (EAC) has long been recognized as a major cause of failure of components and structures but the basic mechanisms of this process are not still fully understood and the development of standardized and practicable methods of testing is a key element in a strategy to understand the kinetics of failure and to provide for mitigation measures. At the JRC-IE, Institute for Energy, a new laboratory for EAC testing of nuclear power engineering materials, in particular core internals materials, has been recently commissioned. The main part of the facility consists of a pneumatic servo-controlled fracture mechanics loading system for 3-point-bending tests of fatigue pre-cracked SEN(B) specimens of different sizes, in a high temperature and pressure autoclave. A first test campaign have been carried out and focused on comparison of the results obtained on 10×10×55 and 3×4×27 mm 3 SEN(B) 316L stainless-steel specimens loaded by constant displacement rate increase tests in typical BWR conditions. The results led to determination of the influence of the loading rate on crack initiation, comparison of the results measured on different size specimens, and verification of the usability of LEFM and EPFM parameters for evaluation of the results.

Molecular and microdeformation characteristics of ethylene-propylene copolymers during tensile loading

The microstructural modification during uniaxial tensile deformation of ethylene-propylene diblock copolymers (EP copolymers) at varying displacement rates was studied using atomic force microscopy (AFM) and Raman spectroscopy. Characterisation by AFM of the undeformed surface of the two copolymers (designated EP-M and EP-TC) indicated differences in arrangement (regular or irregular) of fibrils depending on their melt flow conditions. Type EP-M is a long chain copolymer manufactured with restricted flow, whereas EP-TC is a short chain copolymer obtained by controlled rheology. The microfibrils in both copolymers exhibited small kinks/nodules of ethylene-propylene. At the molecular level, long chain EP-M copolymer exhibited greater non-uniformity in the alignment of chains of molecules in comparison with short chain EP-TC copolymer. Atomic force micrographs taken at different fields of view for long chain EP-M copolymer tensile deformed at a low displacement rate indicated excessive stretching and merging of fibrils/microfibrils in the direction of the tensile axis, whereas short chain EP-TC copolymer exhibited reduced stretching of fibrils and microfibrils. With a subsequent increase in displacement rate of the tensile test, long chain EP-M copolymer continued to stretch along the tensile direction, but with reduced ability for stretching and merging of fibrils/microfibrils. On the other hand, tensile deformation of short chain EP-TC copolymer at a high displacement rate was irregular, and the fibrils/microfibrils were not preferentially stretched in the direction of tensile stress. The irregular deformation behaviour was a consequence of reorganisation of the microstructure. At the molecular level, stretching of individual molecular units occurred in both cases with an increase in displacement rate. However, the differences between the two copolymers were insignificant. Raman spectroscopy indicated that the rate of shift of frequency of Raman band per percentage strain was only marginally greater for long chain EP-M copolymer in comparison with short chain EP-TC copolymer, confirming AFM observations and suggesting only small differences in molecular deformation between the two copolymers.

Effect of loading rate on endplate and vertebral body strength in human lumbar vertebrae

Previous studies have implied that increases in loading rate resulted in changes in vertebral mechanical properties and these changes were causative factors in the different fracture types seen with high-speed events. Thus many researchers have explored the vertebral body response under various loading rate conditions. No other study has investigated the role of the endplate in high-speed vertebral injuries. The current study determined changes in the endplate and vertebral body strength with increases in displacement rate. The endplate and vertebral body failure loads in individual lumbar vertebrae were documented for two displacement rates: 10 and 2500 mm/s. Using cross-sectional areas from the endplate and vertebral body, failure stresses for both components were calculated and compared. Both the endplate and vertebral body failure loads increased significantly with increased loading rate ( p<0.005). Although the vertebral body failure stress increased significantly with loading rate as well ( p<0.01), the endplate stresses did not ( p>0.35). In addition, the endplate and vertebral strengths were not significantly different under high-speed loading ( p>0.60), which inhibits possible predictions as to which bony component would fail initially during a high-speed injury event. It is possible that load distribution may contribute more to the fracture patterns seen at high speeds over vertebral component strength.

Strain-rate sensitivity of the rabbit MCL diminishes at traumatic loading rates

This study was performed to determine whether the viscoelastic behavior of ligaments persists at high rates of loading, such as those associated with sports-related trauma or motor vehicle accidents. Medial collateral ligaments (MCLs) from 22 skeletally mature New Zealand White rabbits were tensile tested quasi-statically and via two impact conditions at displacement rates of 0.17 mm/s ( n=22), 640±160 mm/s ( n=10) and 2500±270 mm/s ( n=12) (corresponding to strain rates of approximately 1.0%/s, 3660%/s and 14,000%/s, respectively). Despite dramatic increases in displacement rate, only a modest strain-rate effect was observed when the specimens tested quasi-statically were compared to those tested via impact (24% and 37% increases in stiffness and failure load, respectively). There were no differences in the structural (e.g. 145±30 and 136±29 N/mm stiffness values, respectively) or failure properties (e.g. 434±91 and 443±154 N failure load values, respectively) of the two impact-tested groups. Our findings suggest that the rabbit MCL is not viscoelastic at loading rates approximating those associated with high-energy trauma.

Effects of loading rate on strength of the proximal femur

Results from previous quasi-static mechanical tests indicate that femurs from elderly subjects fail in vitro at forces 50% below those available in a fall from standing height. However, bone is a rate-dependent material, and it is not known whether this imbalance is present at rates of loading which occur in a fall. Based on recent data on time to peak force and body positions at impact during simulated falls, we designed a high rate test of the femur in a loading configuration meant to represent a fall on the hip. We used elderly (mean age 73.5 +/- 7.4 (SD) years) and younger adult (32.7 +/- 12.8 years) cadaveric femurs to investigate whether (1) the strength, stiffness, and energy absorption capacity of the femur increases under high rate loading conditions; (2) elderly femurs have reduced strength, stiffness, and energy absorption capacity compared with younger adult femurs at this loading rate; and (3) densitometric and geometric measures taken at the hip correlate with the measured fracture loads. Femurs were scanned using dual-energy X-ray absorptiometry (DXA) and then tested to failure in a fall loading configuration at a displacement rate of 100 mm/second. The fracture load in elderly and younger adult femurs increased by about 20% with a 50-fold increase in displacement rate. However, energy absorption did not increase with displacement rate because of a twofold increase in stiffness at the higher loading rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Geometric and numerical model of progressive limb rotation in detachment folds

A simple, area-balanced, geometric model of progressive limb rotation in detachment folds allows the quantification of displacement, uplift, and rotation and the assessment of their effect upon growth strata geometries. Translation of this geometric model into a velocity model of deformation allows the modeling of associated growth strata resulting from background sedimentation and local erosion, transport, and deposition. We show that with constant displacement and sedimentation rate, this model predicts a progressive unconformity, indicating the onlap and eventual overlap of the fold limb caused by a decreasing uplift rate. This decrease is a consequence of the kinematics of progressive limb rotation. Increases in displacement rate, with sedimentation rate kept constant, can lead to offlap and angular unconformities, although subsequent onlap does not necessarily reflect a return to a lower displacement rate. Modeled growth strata geometries exhibit many of the features reported from the literature.

Semiconductor amorphization during irradiation with various particles

Abstract Based on the previously suggested ideas on various possibilities of defect formation during particle bombardment and on monocrystal damage a general description of the laws of semiconductor amorphization process by particle irradiation was developed. It is based on the necessity of radiation structural defects accumulation in the quantities sufficient for a transformation of a single crystal into the amorphous state without using various amorphization mechanisms of the bombarding particles. In the case of low temperature bombardment (100 K) with various ions from helium to bismuth with displacement rates of 1.2-53 · 10−16 part−1 dpa · cm2 it is sufficient to displace several percent of silicon atoms from their lattice sites. When the target temperature rises a damaging dose is necessary which provides more than a ten-fold displacement of each silicon atom. The determined shift of the amorphization dose temperature dependence curve towards higher temperatures with the increase of displacement rate...