Two-parameter Weibull Distribution Function Research Articles

Effects of basalt fibre and rubber particles on the mechanical properties and impact resistance of concrete

The application of waste rubber particles and basalt fibre (BF) in concrete can not only improve the performance of the resulting concrete but also alleviate the environmental pressures related to waste tire disposal. In this study, the impacts of rubber particles and BF on the mechanical and impact performance of concrete are experimentally investigated. Additionally, the macroscopic test phenomenon is explained based on the appearance of the microstructure. The results show that for basalt fibre-reinforced concrete (BFC), when the BF content increases from 0 to 0.4 %, the cube compressive strength and elastic modulus decrease from 71.5 MPa to 62.5 MPa and 44.5 GPa to 41.0 GPa, respectively, while the bending strength increases from 5.9 MPa to 6.6 MPa and then decreases to 6.3 MPa. A BF content of 0.3 % is selected to prepare basalt fibre-reinforced rubber concrete (BFRC). As the rubber particle content of BFRC increases from 0 to 20 %, the cube compressive strength, elastic modulus and bending strength decrease from 64.3 MPa to 51.5 MPa, 41.9 GPa to 33.5 GPa and 6.6 MPa to 5.9 MPa, respectively. However, the reduction rate of the mechanical properties of BFRC is approximately half that of fibre-free rubber concrete at the same rubber content. The shapes of the stressstrain curves of the BFC and normal concrete (NC) are similar, whereas the descending stage of the stressstrain curve of the BFRC is obviously gentler, and the whole BFRC stressstrain curve is much fuller, reflecting typical ductile failure. Both the BF and rubber particles contribute to impact performance improvement, but the effect of the rubber particles is much greater than that of the BF. Compared with that of the NC, the incorporation of 0.3 % BF increases the initial crack impact energy (W1) and final crack impact energy (W2) by 71 % and 79 %, respectively, but when 20 % rubber particles are additionally added, the increase rates of W1 and W2 reach 668 % and 686 %, respectively. The impact life evolutions of BFC and BFRC can be described effectively by a two-parameter Weibull distribution function.

Research on freeze-thaw damage and life prediction model of polyethylene fiber-reinforced cementitious composites based on reliability analysis

Engineered Cementitious Composite (ECC), is a fiber-reinforced cementitious composite with excellent ductility, toughness, impact resistance and multi-crack development characteristics. In addition to the excellent mechanical properties, the durability of ECC has also received equal attention. In order to investigate the frost resistance of polyethylene fiber-reinforced cementitious composites (PE-ECC), PE-ECC and normal concrete (NC) specimens were subjected to different numbers of freeze-thaw cycles, and the changes in compressive strength, mass loss rate and relative dynamic modulus of elasticity of the specimens before and after freezing and thawing were tested, so as to compare the freeze-resistant properties of PE-ECC and NC. A freeze-thaw damage model was established using the two-parameter Weibull distribution function, and the freeze-thaw reliability of NC and PE-ECC was analyzed based on the Wiener process analysis, based on which a life prediction model was established to predict the life of NC and PE-ECC under freeze-thaw environment. The results show that after 200 freeze-thaw cycles, the compressive strength loss rate, mass loss rate and the relative dynamic elastic modulus loss rate of NC and PE-ECC are 32.97%, 2.35%, 50.28% and 17.28%, 0.71%, 6.57%, respectively, and the damage indexes of PE-ECC are lower than that of NC, and the NC after 200 freeze-thaw cycles has reached the standard of freeze-thaw damage, while PE-ECC is still at a lower level of freeze-thaw damage; it shows that the frost resistance of PE-ECC is better than that of NC, and the addition of PE fibers can effectively improve the frost resistance of concrete; the results of the damage model and the reliability analysis coincide well with the experimental results, and the results of life prediction are given in some cold regions, which can provide a basis for the application of PE-ECC in practice.

Impact resistance of macro and micro steel fibre reinforced self-compacted concrete (SFRSCC) with modelling and reliability analysis

Adding steel fibres can transform the brittle characteristic of concrete into a ductile state. The objective of the current study is to test the impact resistance of macro and micro steel fibre-reinforced self-compacting concrete (SFRSCC) experimentally by applying a simulated drop-weight impact, as well as statistically and through reliability studies. Cube specimens were used for the experiment. The inclusion of macro and micro steel fibre greatly increased the concrete mixture’s impact resistance. It is observed that the volume fraction of 0.75 and 0.50% of macro and micro steel fibre has improved impact resistance with an increase in the percentage of energy absorption of 216.21 and 240.53%, respectively. All the concrete samples exhibited the same failure pattern. Using Response Surface Methodology, the impact resistance of SFRSCC mixtures can be accurately predicted. The first and failure cracks (N1 and N2) follow a two-parameter Weibull distribution function of drop-weight impact test.

Analysis of fracture state and fatigue life of high modulus carbon fiber wrapped composite barrel

High-modulus Carbon Fiber-reinforced Polymer composites are widely used in critical industries due to their exceptional mechanical properties. However, the fatigue and fracture of high modulus carbon fiber materials are currently poorly studied. For this purpose, the NOL ring fatigue tensile testing is referenced and improved to investigate the performance and service life of high-modulus carbon fiber wound barrels. NOL ring specimens, made of M40 carbon fiber material, are subjected to quasi-static tensile and fatigue tests. The fracture state and characteristics of high modulus materials during fatigue are analyzed. Two-parameter Weibull distribution function is used to analysis statistically the fatigue life results of composite samples. Then, the life curve is drawn for different stress amplitudes. Additionally, the fiber fracture surface is observed under a high-power microscope. The fiber fracture model under brittle fracture is established. The results indicate that the fracture characteristics and mechanisms of high-modulus materials differ from those of high-strength materials, necessitating different fatigue life assessment methods. The fatigue failure of high modulus fibers exhibits brittle fracture similar to quasi-static loss, with flat fracture surfaces and minimal cumulative damage. The failure mechanism is accompanied by brittle fractures with a small amount of fiber pulled out.

Experimental investigation on the impact properties and microstructure of recycled steel fiber and silica fume reinforced recycled aggregate concrete

With the continuous development of the economy and society, the production of solid waste is increasing. Construction and demolition waste (CDW), used tires and silica fume are the main components of solid waste. Recycling these materials will reduce resource pressure, decrease carbon emissions and protect the environment, while bringing certain economic benefits. This study focused on the influence of the synergistic effect of recycled steel fibers (RSF) and silica fume on the mechanical properties and impact resistance of recycled aggregate concrete (RAC). The mathematical statistical model of Weibull distribution was adopted to depict the impact results. In addition, the microstructure of the interfacial transition zone (ITZ) between the cement paste and the aggregate/fiber was researched by scanning electron microscopy (SEM). Results revealed that the synergistic effect of RSF and silica fume significantly improved the impact resistance of RAC. Especially the specimen containing 10% silica fume and 0.75% RSF performed the best properties, the first crack impact and failure impact energy increased by 421.9% and 461.3%, the net-gain in them by the synergistic action of silica fume and RSF with values of 102.7% and 115.3%. The distribution law of the impact life for RSF reinforced RAC can better describe by the two-parameter Weibull distribution function. Impact resistance life was predicted corresponding to reliability levels. SEM investigations revealed that the ITZ between cement and aggregate/RSF significantly improved by mixing silica fume.

Damage softening model and behavior of reinforced soil interface based on the Weibull distribution

A damage-softening model for a reinforced soil interface is proposed based on the trilinear model of a reinforced soil pullout interface, aiming at the softening phenomenon of the geogrid reinforced soil interface during the pullout process and considering the damage softening of the reinforced soil interface during the pullout process. The damage variable factor D is introduced, and it is assumed that D is a function of the interface displacement. The two-parameter Weibull distribution function is used to express the damage evolution law of the reinforced soil interface. Based on the basic control equation of the reinforced soil interface, the calculation model of the stress state of the geogrid at different stages under the pullout load is deduced. To verify the accuracy and applicability of the model, the prediction results of the model are compared with the test results and the ideal elastic–plastic model, hyperbolic model, elastic–exponential softening model, and the damage softening model based on a lognormal distribution function proposed in this paper. The distribution of interfacial shear stress is studied, and the influence of parameters at each stage is analyzed. The results show that in the elastic stage, with the increase of shear stiffness, the maximum shear stress at the interface increases, and the curvature of the curve also increases, while the elastic modulus is the opposite. In the softening stage, with the increase of softening length, the peak value of the curve moves to the free end. In the residual stage, the shear stress increases from the drawing end to the free end and tends to the residual stress. The research results are in accordance with the actual situation and can be applied to reinforced soil engineering.

Flexural Strength Properties of Five Different Monolithic Computer-Aided Design/Computer-Aided Manufacturing Ceramic Materials: An In Vitro Study.

Objective The purpose of this in vitro study is to compare the flexural strength and Weibull modulus of 5 different monolithic computer-aided design/computer-aided manufacturing (CAD/CAM) ceramics. Methods A total of 50 specimens were fabricated, 10 from each of the following materials: lithium disilicate-based ceramic (IPS e.max CAD), zirconia -reinforced lithium-silicate ceramic (Vita Suprinity), leucite-based glass ceramic (IPS Empress CAD), and two zirconia-based ceramics (Zenostar and CopraSmile). The specimens were 4 mm wide, 2 mm thick, and 16 mm long. Flexural strength test was executed using a universal testing machine (Model 5980, Instron Industrial Products, Norwood, MA, USA). The two-parameter Weibull distribution function was used to analyze the variability of flexural strength values. Statistical analysis was performed on SPSS Version 23 (IBM Corp., Armonk, NY, USA) using one-way analysis of variance (ANOVA) and post-hoc Tukey's test. Results Suprinity had the highest Weibull modulus value, while Empress CAD displayed the lowest value. One-way ANOVA showed significant difference in the flexural strength between the different materials tested (p<0.05). Post-hoc analysis revealed significant differences among all the test groups in terms of flexural strength. Zenostar presented the highest mean flexural strength value (1033.90 MPa), while Empress CAD had the lowest value. Conclusion High-translucency zirconia had superior flexural properties than translucent zirconia, lithium disilicate ceramics, zirconia-reinforced lithium silicate ceramics, and leucite-based glass ceramics.

Feature Extraction and Pattern Recognition Algorithm of Power Cable Partial Discharge Signal

The degree of insulation aging of power cables is closely related to their partial discharge (PD) level, so the analysis of PD signals can be used to realize the cable condition detection. However, after performing online detection of PDs on power cables, the collected signals always contain interference signals due to the influence of electromagnetic interference in the field. In order to identify each type of local discharge signal from the interference signal, this paper proposes a clustering identification algorithm for local discharge signals, which mainly involves pulse extraction, feature parameter extraction and clustering identification process. The algorithm first extracts the pulse signal by combining the amplitude–time threshold method and the time domain energy method, then obtains the feature vector of the signal according to the synchronous multi-channel method, designs a fuzzy C-mean clustering algorithm based on subtractive clustering to determine the initial clustering center to cluster the samples and finally analyzes and checks the clustering results according to the phase resolved PD (PRPD) of a single class of signals and the fit of the two-parameter Weibull distribution function. The clustering results were analyzed and examined. The experimental results show that the proposed algorithm can extract pulse signals efficiently and accurately, and the synchronous multi-channel method can characterize pulse signals better. Meanwhile, the algorithm can determine the optimal number of classes adaptively according to the clustering effectiveness function and adopt subtractive clustering to initialize the clustering center, which can approach the optimal solution faster, and can effectively cluster a variety of discharge signals, so as to realize the type identification of single-class discharge signals.

Experimental study on uniaxial creep characteristics of sandstone with pre-peak unloading damage

Deep resource extraction has been affected by the complex geological environment of "three highs and one disturbance" for a long time. The surrounding rocks experience strong unloading stress disturbance during the underground resource extraction. The creep characteristics of the perimeter rocks are of great theoretical and practical value. Firstly, the triaxial pre-peak loading and unloading tests on the prepared samples are conducted on the intact rock samples using the TAW-200 rock mechanics test system. Then the rock samples with different degrees of pre-peak unloading damage were prepared under the condition of pre-peak yield. Finally, the uniaxial creep tests were carried out to study the uniaxial creep mechanical properties. The results show that the wave velocities of the damaged rock samples are reduced to different degrees compared with those of the intact rock samples, the creep of the pre-peak unloading damaged rock has a time-dependent damage effect, and the study results are similar to those of the conventional uniaxial creep test of the white sandstone. The instantaneous strain at all stress levels of the damaged rock samples increased gradually with the stress level, which is consistent with the non-linear functional relationship; Based on the time-dependent damage effect, the two-parameter Weibull distribution function was introduced into the West Plains viscoelasticity model, and a creep damage model for white sandstone was proposed. The improved Nishihara model can simulate the uniaxial creep characteristics of each damaged rock sample at various stress levels.

Evaluation of wind energy potential at four provinces in Morocco using two-parameter Weibull distribution function

In the last years, the use of wind turbines for power generation has increase due to the advance's technology used and the stable cost. In this paper, due to the low investment in the desert regions of Fezouata, Ouijjane, El Ouatia, and Taroudannt in Morocco, we have considered wind resources as an ideal option. Using meteorological statistics, Weibull's distribution function was able to estimate the wind power and potential of four various wind turbines for each site with various nominal powers, ranging from 250 kW to 2000 kW, for use in wind farms. 24 years of wind speed data to fit the Weibull distribution. For the four provinces examined, the annual mean value of wind speed and frequency distributions were collected. The desert province of El Ouatia shows that it is economically feasible to install a wind farm for the production of green energy.

ASSESSMENT OF WIND ENERGY POTENTIAL FOR ACCRA, GHANA USING TWO PARAMETER WEIBULL DISTRIBUTION FUNCTION

This study investigates the predictive ability of two-parameter Weibull distribution function for Accra, Ghana using fifteen years (2002 – 2016) meteorological parameter of monthly mean wind speed data. The monthly and annual averaged wind speed was estimated to be . The annual mean values of the maximum energy – carrying wind speed and most probable wind speed were found to be and respectively. The two parameters of the Weibull statistics found in this study for Accra were within the range for the shape parameters and for the scale parameters. The results of the wind power density indicated that the location has a good prospect for wind power generation with the highest value of found in September, 2006. The linear relationship between the monthly mean wind power density and mean wind speed shows that a perfect correlation with coefficient of correlation of 99.3 % exists between them. The results obtained from this study revealed that the Weibull function was found appropriate for analyzing measured wind speed data and in predicting the wind power density for the region under investigation. Therefore, Accra has an excellent prospect for wind power generation

Effect of loading frequency on the fatigue life in compression of natural hydraulic lime mortars

This paper focuses on the study of the influence of the loading frequency on the fatigue life in compression of natural hydraulic lime (NHL) mortars. For this purpose, fatigue tests were performed under three different loading frequencies: 0.05 Hz, 0.5 Hz, and 5 Hz. The maximum and minimum stresses applied in the fatigue tests were 85% and 20% of the compressive strength of the mortar, respectively, and the runout limit was set at around three days. It is observed that the NHL mortar is sensitive to the loading frequency; that is, for higher frequencies, more cycles are resisted by the specimens. Concerning the secondary strain of the fatigue creep curves, the Sparks and Menzies law was satisfied independently of the loading frequency. This law is useful to predict the number of cycles to failure of runouts if the secondary strain is known. In addition, given the high scatter of results, a probabilistic treatment is applied. Firstly, they were fitted to a two-parameter cumulative Weibull distribution function. Secondly, the results were fitted to a probabilistic fatigue model based on the initial distribution. With it, one can obtain the failure probability of the material for any given value of loading frequency. Finally, we observed an increase in the residual strength after fatigue in comparison to the static compression tests of around 40%. Through mercury intrusion porosimetry tests, it is concluded that a possible chemical curing of the material could have occurred induced by the cyclic loads.

Viscoelastic Damage Characteristics of Asphalt Mixtures Using Fractional Rheology.

The mechanical behavior of asphalt mixtures at high stress levels are characterized by non-linear viscoelasticity and damage evolution. A nonlinear damage constitutive model considering the existence of creep hardening and creep damage mechanisms in the entire creep process is proposed in this study by adopting the fractional rheology theory to characterize the three-stage creep process of mixtures. A series of uniaxial compressive creep tests under various stresses were conducted at different temperatures to verify the model. The results indicated that the model predictions were in good agreement with the creep tests. The relationship between the model parameters and applied stresses was established, and the stress range in which the mixture exhibited only creep consolidation was obtained. The damage to the asphalt mixture was initiated in the steady stage; however, it developed in the tertiary stage. A two-parameter Weibull distribution function was used to describe the evolution between the damage values and damage strains at different stress levels and temperatures. The correlation coefficients were greater than 0.99 at different temperatures, indicating that a unified damage evolution model could be established. Thus, the parameters of the unified model were related to material properties and temperature, independent of the stress levels applied to the mixtures.

Technical Assessment of Wind Energy Potentiality in Malaysia Using Weibull Distribution Function

In this paper, an assessment of the wind characteristics and wind power potentials in three different stations (Chuping, Kuantan and Melaka) in Malaysia has been analyzed at 80 m height. The assessment technique was based on the two-parameter Weibull distribution function over three recent consecutive years (2018-2020) while aiming to establish the potentiality of the wind as a source of power generation in these sites. The results demonstrate that the monthly highest mean wind speeds were 4.42 m/s, 2.96 m/s and 2.17 m/s at Melaka, Kuantan and Chuping, respectively. The highest most probable wind speed was 4.70 m/s and the wind speed carrying maximum energy was 1.74 m/ both speeds occurred at Maleka in 2019. The yearly highest Weibull shape parameter was 1.69 and the scale parameter was 2.96 m/s. Among the three stations, Melaka has shown the highest wind power potentials with an average value of 26.10 W/m2 followed by Kuantan with 12.71 W/m2 and Chuping with 6.80 W/m2 wind power density. The corresponding wind energy densities were 595.58 kWh/m2/year, 111.37 kWh/m2/year and 228.65 kWh/m2/year for Chuping, Kuantan and Melaka station, respectively. The prevailing wind directions are northeast at both Kuantan and Melaka station, west and southwest direction at Chuping station. It is therefore concluded that the potentiality of the wind power of the sites covered in the present study is only feasible for small-scale power generations.

Experimental investigation on the rotating bending fatigue behaviour of glass and carbon fibre-reinforced epoxy composites

ABSTRACT Composite materials have seen a substantial increase in use in aerospace, aircraft and automobile industries as a result of the high expectations on material performance raised by emerging technologies. Fatigue loads are mostly inevitable in these applications. As a consequence, in addition to static strength, current designs require fatigue analysis. Hence, in this investigation, hollow cylindrical composites, constituted by glass and carbon fibres with an epoxy matrix, were considered for evaluating their static and fatigue behaviour. These specimens were tested in load control mode using an in-house built rotating bending fatigue machine at a test frequency of 10 Hz with zero mean stress. To determine the scatter in fatigue life of the developed composite specimens and to create life distribution graphs at any probability of survival percentage, the two-parameter Weibull distribution function was used. Results indicate higher shape parameters for both the composites, at lower stress levels, which represent less dispersions in the fatigue life under high cycle fatigue. Matrix cracking, interfacial delamination, fibre pull-out, and longitudinal splitting of the matrix along fibre failures are observed using a scanning electron microscope.

Enhancement of wind energy resources assessment using Multi-Objective Genetic algorithm: A case study at Gabal Al-Zayt wind farm in Egypt

ABSTRACT Estimation of wind speed distribution is essential for wind energy resources assessment, design of wind farms, and selection of suitable wind turbines. Two-parameter Weibull distribution function is widely used worldwide for wind energy resources assessment. As a case study, 1one-year field measurements at Gabal Al-Zayt wind farm in Egypt are used to estimate the Weibull parameters and to accurately assess the wind energy resource. In this work, seven statistical methods are adopted to estimate the Weibull parameters and their estimation accuracy is compared based on some common estimation errors. However, the improvement in one estimation error does not necessarily improve other types of errors. Consequently, a multi-objective genetic algorithm (MOGA) is adopted to investigate the tradeoffs among the competing estimation errors and to enhance the assessment of wind energy resources. The results show significant improvement in the estimation accuracy of the Weibull parameters using MOGA as compared to conventional statistical estimation methods. On the other hand, the case study at Gabal Al-Zayt wind farm reveals that the selection of wind turbines does not depend only on wind characteristics of the site but also on its environmental characteristics.

DISTRIBUTION OF INDIVIDUAL WAVE OVERTOPPING VOLUMES ON A SLOPING STRUCTURE WITH A PERMEABLE FORESHORE

Maximum wave overtopping volumes on sea defences are an indicator for identifying risks to people and properties from wave hazards. The probability distribution of individual overtopping volumes can generally be described by a two-parameter Weibull distribution function (shape and scale parameters). Therefore, the reliable prediction of maximum individual wave overtopping volumes at coastal structures relies on an accurate estimation of the shape factor in the Weibull distribution. This study contributes to an improved understanding of the distribution of individual wave overtopping volumes at sloping structures by analysing the wave-by-wave overtopping volumes obtained from physical model experiments on a 1V:2H sloped impermeable structure with a permeable shingle foreshore of slope 1V:20H. Measurements of the permeable shingle foreshore were benchmarked against those from an identical experimental set-up with a smooth impermeable foreshore (1V:20H) of the same geometry. Results from both experimental set-ups were compared to commonly used empirical formulations, underpinned by the assumption that an impermeable foreshore exists in front of the sea structure. The effect on the shape factor in the Weibull distribution of incident wave steepness, relative crest freeboard, probability of overtopping waves and discharge are examined to determine the variation of individual overtopping volumes with respect to these key parameters. A key finding from the study is that no major differences in Weibull distribution shape parameter were observed for the tested impermeable and permeable sloped foreshores. Existing empirical formulae were also shown to predict reasonably well the Weibull distribution shape parameter, b, at sloping structures with both impermeable and permeable slopes.

Tensile Strength Study of Stainless-Steel using Weibull Distribution

In the present study, the distribution pattern of the ultimate tensile strength of 304-grade stainless steel was investigated using a two-parameter Weibull distribution function. During tensile testing, it was observed that the ultimate tensile strength varied from specimen to specimen (ranges from 878 to 1006 MPa). The results have revealed that the distribution pattern of the tensile strength can be described by the two-parameter Weibull distribution equation. Moreover, the fracture statistics of the stainless steel were examined by plotting the survival probability of the specimen against the applied stress to the specimen. It has been observed that the relationship between the survival probability and the applied stresses can be described by the Weibull model. It also provides design engineers with a tool that will help them to present the necessary mechanical properties with confidence.

Predictive model and assessment of the potential for wind and solar power in Rayak region, Lebanon

With the increasing consumption of fossil fuel, reducing greenhouse gas (GHG) emissions has become a serious issue that has attracted worldwide attention. Therefore, Lebanon is currently interested in utilizing renewable energy technologies to reduce energy dependence on oil reserves and GHG emissions. The present study is focused on solar and wind power potential and the economic viability of wind/solar systems for the Rayak region in Lebanon for the first time. The input data sources for the study including the Meteorological data for wind speed and NASA database for solar energy. In the assessment of wind energy, a two-parameter Weibull distribution function was used to analyze the characteristics of wind speed. Yearly and seasonal Weibull parameters were calculated for 10 m height using the Maximum likelihood method. In addition, yearly and seasonal wind power density values were calculated. The results showed that the mean annual wind speed and wind power density values were 5.884 m/s and 124.534 W/m2, respectively, during the investigation period. It can be concluded that the value of wind power density at the region was classified as marginal wind power potential and high-scale wind turbines can be used to gather wind energy potential in the region. Furthermore, predicting wind speed depends on various atmospheric factors and random variables. Therefore, 63 ANN models are developed by varying the meteorological parameters to predict the daily wind speed in the selected region. All the models with various combinations are validated and the performances of the models are analyzed using root mean squared error. The results demonstrated that the most relevant input variables for predicting the daily wind speed were found to be temperature, pressure, and relative humidity. In the assessment of wind energy, average monthly global solar radiation data were evaluated. It is found that the annual global solar radiation was 1877.41 kWh/m2, which indicates the selected region has high solar resources and is categorized as an excellent potential class. Moreover, this study provides a comprehensive and integrated feasibility analysis of 100 MW grid-connected wind and solar projects economic projects that can be developed in the country to reduce the electricity crisis and GHG emissions. Several different economic and financial indicators were calculated. The results indicate that the wind farm is a more economical option than the solar plant because of the higher values of NPV, BCR, ALCS, and IRR as well as the lower values of EB, SB, and LCOE.

WIND ENERGY EVALUATION AND TURBINE IDENTIFICATION FOR POWER GENERATION IN SOME SELECTED AREAS IN NIGERIA

In this paper, the wind power potentials as well as wind speed characteristics of four selected locations in the North-Central (Ilorin and Makurdi) and North-East (Gombe and Maiduguri) parts of Nigeria are investigated. The data used are obtained from Nigeria Meteorological Agency (NIMET) between the durations of 11 and 54 years, measured at an anemometer height of 10m. The analysis of the data is carried out using a two-parameter Weibull Distribution Function (WDF). The most probable wind-speed and the wind-speed carrying the maximum energy were also evaluated. The capacity factor estimation is then used to identify the most suitable turbine for the sites. The results obtained show a monthly mean wind-speed of 4.50 m/s, 3.72 m/s, 4.77 m/s and 5.34 m/s for Ilorin, Gombe, Makurdi and Maiduguri respectively, while the wind-power densities were 67.74 W/m2, 40.87 W/m2, 79.52 W/m2 and 107.49 W/m2 respectively for the same sites.