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We verify experimentally the recommendations put forward in the International Standards for anchorage in concrete concerning the assessment of the load-carrying capacity of anchors (the pull-out force) embedded in natural rock material. Regarding the predicted extent of surface failure we have shown, in earlier studies, substantial discrepancies between the strength test results for anchorages in the rock mass and the established standard recommendations for anchorages in concrete. As regards the industrial practice and the goals of the reported project, simplified calculation procedures are sought that will facilitate the selection of optimal configurations for the layout of anchor holes, while being computationally effective and applicable in the industry-specific conditions.

The experimental test results of glued-mechanical couplings of shaft — bush made with the use of anaerobic sealants are presented. Quantitative estimations of the surface layer quality of the mating parts were obtained that made possible to estimate values of surface waviness of the shaft and the bush. The methodology of the waviness determination of cylindrical couplings is described. The influence of fit on mechanical strength of the shaft — bush coupling depending on properties of a used anaerobic sealant was established.

Background/Objectives: FRP (Fiber Reinforced Polymer) has a wide range of application areas within the construction industry and is used in various forms and shapes, primarily for maintenance purposes. Using FRP has numerous advantages and disadvantages driven by several factors, including the country where it is used. The present paper focuses on the feasibility of using FRP in Afghanistan, considering load carrying capacity, cost, time efficiency, and environmental concerns as the main parameters. Method: In this numerical study, RC-jacketing and FRP-wrapping methods were evaluated for strengthening/repairing RC columns, and a comparison of the two methods was carried out to understand which approach better meets the maintenance needs in Afghanistan. Findings: As a result, the RC-jacketing method was more efficient in terms of cost and strength, while the FRPwrapping method proved its efficiency in terms of time and lower emission of CO2. Moreover, the RC-jacketing method was found to be more suitable and aligned with the country’s current architecture. Overall, as the cost is the leading parameter in a developing country like Afghanistan, RC-jacketing was more suitable for conducting the maintenance work. Additionally, the authors also recommended using the FRP-wrapping method in some particular circumstances where the RC-jacketing method was believed to be less efficient. Keywords: RC-Jacketing; FRP-Wrapping; retrofitting; reinforced concrete columns; strength; cost-effectiveness

Many bridges built during the colonial times in Australia have timber girders as load transferring elements and they are still in service with increased traffic loads and consistent deterioration. Most of the timber girders in those bridges are notched at the ends for better seating arrangement. Therefore, it is necessary to quantify the strength characteristics of notched girders in order to ensure structural safety and make necessary intervention to extend their service lives. Hence experimental tests were conducted on the notched rectangular timber girder samples with three different notch depths (i.e.10%, 15% and 30% of the depth of beam) having the notched angle of 1:4. Consequently, detailed finite element models were developed for notched timber girders, and the models were validated with experimental results. The validated model was used to predict the shear and flexural strengths and stiffnesses of typical circular and rectangular timber girders with two different spans (i.e. 6 m and 9 m), three different notch angles (i.e. 1: 0, 1:2 and 1:4) and three depths (i.e.15%, 30% and 45% o of the depth of beam). Strength data developed for notched timber were used to compare the applicability of the design provisions in various timber design standards. Experimental and finite element model test results show that when the notch depth increased from 15% to 45%, the load carrying capacity of rectangular timber girder was reduced by 50%. Whilst, the reduction of the load carrying capacity of the corresponding circular timber girder was slightly low (i.e. 37%). Further, when the notched angle changes from 1:0 to 1:4, the load carrying capacity of circular and rectangular girders increased about 50%, 69% and 110% for the notch depths 15%, 30% and 45%, respectively.

This paper explores the potential use of a woven polypropylene textile for encapsulating stone columns and improving performance of a local soft soil in Warangal city of India. A series of axial load tests were performed on stone columns of various diameters and under various encapsulation conditions that include single and double layers and other combinations. Load carrying capacity of stone column increased twice its original capacity when encapsulated with different geofabric materials. Performance enhancement strongly correlated to the tensile strength of encasement material and encapsulation condition. In addition, the influence of lateral thrust on group of stone columns arranged in square and triangular patterns were investigated. Irrespective of the material used, lateral displacement reduced by half for encased stone columns. Apart from tensile strength of encasing material, the amount of material used for encasement in the form of additional encasement layer was found to be crucial. The cost of using the polypropylene encasing material is only a third of the commercial geotextiles; however, the performance is inferior to woven geotextiles but far superior to non-woven geotextiles.

One fifth of the land mass in India is covered by black cotton soil (BCS). Due to low permeability, poor strength and high compressibility, they pose huge engineering problems. In the present study, the influence of stone column on the consolidation and strength behaviour of black cotton soil is meticulously studied. Laboratory tests are carried out on both end bearing and floating type stone columns, having diameters (d) 50 mm, 60 mm and 70 mm with l/d ratios 3, 4 and 5 (l being the length of stone column), installed in black cotton soil. The load-settlement and consolidation behaviour of unreinforced and reinforced black cotton soil are compared. It has been found that for d = 60 mm and l/d = 3, the load carrying capacity for reinforced BCS increases by 23% and 20% for end bearing and floating type stone columns, respectively. Moreover the void ratio (e), coefficient of compressibility (av), coefficient of volume change (mv), coefficient of consolidation (Cv), coefficient of permeability (k) and compression index (Cc) of black cotton soils are significantly affected by the l/d ratio and diameter of the stone column. The present study reflects the efficiency of stone columns as suitable ground improvement technique for BCS.

This paper introduces a new approach for predicting load carrying capacity of circular section piles and helical piles in frozen ice-rich soils based on ground's freezing temperature and the temperature-dependent cohesion. Results obtained using this approach were validated against a field measured load carrying capacity for model single-helix helical piles, steel open-ended pipe piles, and cylindrical concrete piles in unfrozen and frozen Leda clay. The piles were first tested before wintertime while the ground was in unfrozen condition. The measured load carrying capacity in the unfrozen condition agreed well with the predicted capacity obtained from a modified previous design model for helical piles and the alpha method for the circular section piles. Modified formulae from these models were developed and used for predicting the load carrying capacity of the test piles in the ground after freezing. The predicted pile capacities agreed well with the measured load carrying capacities in the frozen ground. The introduced design approach was beneficial in providing accurate predictions for different pile types, under different loading conditions, and using readily obtained input parameters (i.e., ground temperature and the temperature-dependent cohesion strength). The presence of a snow layer on the ground surface reduced the frost depth penetration and led to a significant reduction of the load carrying capacity of the test piles particularly the helical piles.

The present work investigates the load carrying capacity of vertically and horizontally reinforced floating stone column group through model testing. Two group arrangements using three and four stone columns for both unreinforced and reinforced conditions are testing under compressive loading. The geotextile reinforcement is provided throughout the stone column length (300 mm) in vertical direction and in form of circular discs at spacing of 30 mm along column length for reinforcing horizontally. The results of load-settlement behavior and failure mechanism of both unreinforced and reinforced group is studied. The testing results indicated reduced lateral bulging and higher stone column load capacity for horizontally reinforced columns in comparison to vertically reinforced. For validation of experimental results, numerical modeling using finite element (FE) code Plaxis 2D has also been conducted. The FE results depict lower load capacity as compared to model testing for settlement of 30 mm. However, the failure mode for both model tests and FE analysis was marked by bulging near the top of stone column and punching. Furthermore, load capacity is also check using empirical relations as given by IS code and previous literature. It is observed that experimental and analytical results are found in good agreement.

In this work, the analysis of the long column loaded biaxially using high performance concrete is carried out. Total four numbers of high performance concrete columns are casted and then tested with biaxial load using loading frame. The compressive strength of the concrete used in columns is from 60 MPa and 80 MPa. After successfully casting of long columns using high performance concrete with 60 MPa and 80 MPa is cured for 28 days. For HPC, the average compressive strength achieved is 67 MPa and 86 MPa for 60 MPa and 80 MPa grades respectively. Biaxially loaded HPC columns at eccentricity of 10% and 20% for 60 Mpa and 80 Mpa grade is studied. The applied loads are in the range of 800 kN to 950 kN to assess the deflection of HPC long columns at different eccentricities. The experimental and FEA analysis was carried out to assess the performance of columns. From experimental and FEA analysis, it was seen that as eccentricity increases the deflection of HPC columns increases. The maximum deflection observed for 80 MPa grade HPC long column with 20% eccentricity. It was seen that, deflections observed for biaxial loading conditions for these fabricated columns are in allowable limits. It was also observed that, load carrying capacity developed in 60 MPa and 80 MPa grade HPC long column is greater than value given in codes.

This paper presents the experimental and analytical investigation carried out on the flexural behaviour of Pultruded Glass Fiber Reinforced Polymer (GFRP) beams infilled with High Volume Fly Ash Engineered Cementitious Composite (HVFAECC). Tests were conducted on two hollow GFRP beams and two GFRP beams infilled with HVFAECC. Load displacement behaviour and load strain behaviour of the beams were investigated. The load carrying capacity of Pultruded GFRP beams infilled with HVFAECC was significantly more than the hollow GFRP beams. Experimental results were also compared with the finite element analysis.

Zahnfußtragfähigkeitskennwerte für Zahnräder werden in der Praxis üblicherweise in Pulsator- oder Laufversuchen ermittelt. In den genannten Prüfverfahren liegen, bedingt durch den Aufbau des Prüfgeräts, unterschiedliche Beanspruchungen in den zu prüfenden Zahnrädern vor. Dies kann dazu führen, dass für das selbe Bauteil je nach Prüfverfahren unterschiedliche Tragfähigkeitskennwerte ermittelt werden. Es wird ein statistisches Modell vorgestellt, das den Einfluss der Zahl der beanspruchten Zähne auf die Tragfähigkeitskennwerte eines Zahnrads berücksichtigt, um eine zuverlässige Auslegung eines Getriebesystems sicherzustellen. Basierend auf der Modifikation eines bestehenden Modells kann ein relevanter statistischer Zähnezahleinfluss im Bereich praxisrelevanter Zähnezahlen nachgewiesen werden. Für die praktische Anwendung wurden aus den Ergebnissen der Auswertung des statistischen Modells einfach anwendbare Methoden zur Umwertung von Festigkeitskennwerten im Auslegungsprozess abgeleitet. Diese ermöglichen eine zuverlässige Auslegung von Getriebesystemen, die im Kontext steigender Leistungsdichte und der Umsetzung von Leichtbaukonzepten zunehmend an Bedeutung gewinnt. Die mathematische Formulierung des Ansatzes ermöglicht die einfache Anpassung für die Auswertung anderer Schadensarten, Verteilungsformen und Versuchsstreuungen.

This study presents the experimental and analytical modelling of externally bonded glass fibre-reinforced polymer (GFRP) sheets for strengthening circular steel tubular short columns. The GFRP sheets are easy to handle due to the lightweight property and the high-strength can provide a degree of restraint to delay buckling of the thin steel wall. Four short columns of cold-formed steel circular hollow section (CHS) were experimentally tested. One column is conventional (without GFRP wrap) and other 3 columns are externally bonded unidirectional (hoop) GFRP sheets which are varying with numbers of layers (1, 2 and 3 layers). In addition to the experimental studies, finite element analysis was also carried out using ABAQUS software. The experimental result shows that the steel tube is strengthened by GFRP sheets and enhances the axial section capacity. The load carrying capacity of externally bonded GFRP column increases about 17%−49% on comparison with the column without confinement. The study also concluded that the column externally warped with 3 layers of GFRP sheet is found to be optimum and it attains maximum load caring capacity. The prediction of analytical results has been found to be in good correlation with the experimented results.

External strengthening using Jacketing technique can suitably use for increasing the Axial and shear strength of RC square Column [1] . This paper includes an experimental investigation for studying the effectiveness and suitability of high performance ferrocement mortar mixes as a retrofitting material and its use as jacket for square columns. The experimental programme included development of high performance ferrocement mortar mix by adding 10% of silica fumes and 1% of super plasticiser and its use in retrofitting of square column specimens which were either intact or distressed earlier to certain level [2] . The experimental programme consisted of testing 2 controlled specimens and 6 retrofitted specimens initially distressed to 80–85% of theoretical stress level, repairing, and retrofitting prior to testing. The control specimens were of dimension 100mmx100mm and 500 mm height, cast in M30 conventionally vibrated concrete, reinforced longitudinally with four bars of 8 mm diameter and six lateral ties of 6 mm diameter as transverse reinforcement [3] . Three different mixes proportions of 1:1.5, 1:2, 1:3, were used for jacketing around the columns. The jacket was reinforced with mild steel welded wire mesh 50 mm × 50 mm made of 1.16 mm diameter wire. The retrofitted specimens were tested after 28 days of curing. Carbon Fibre Reinforced Polymer (CFRP) Sheet is provided at top and bottom of the specimens. And then the results are compared at the end the Retrofitted specimen of 1:1.5 Ferrocement mix has more Load carrying capacity than other Ferrocement mix when compared with controlled of 8.85%.

Air pollution in major cities of developing countries is a matter of great concern for managers, scientists, and people. In recent years, many studies have been done to simulate and forecast air quality for big cities in Vietnam as well as in the world with many air quality models have been used. However, studies using air quality models to evaluate the capacity of receiving air emission load in the atmospheric environment in local scale have not been carried out, especially in Vietnam. Therefore, the objective of this study is to assess load-carrying capacity in the atmospheric environment on a local scale for a smaller city at Mekong Delta, with a case study of Can Tho city, Vietnam. The FVM-TAPOM model system was established for the study area with the smallest grid resolution of 2km x 2km. The study results show that the atmospheric environment in Can Tho city still can receive more air emissions according to two seasons of the year (dry and rainy seasons) which are different depending on the seasonal wind direction. The central districts of Can Tho city (Ninh Kieu, Cai Rang, Binh Thuy, O Mon, and Thot Not) can only receive a smaller amount of emissions compared to the others (Vinh Thanh, Co Do, Thoi Lai, and Phong Dien). The amount of air emissions that can be received at the central districts is as follows: CO from 82,000 to 172,000 tons/year/district (696 – 2,142 tons/year/km2); SO2 from 3,800 to 4,900 tons/year/district (31 – 56 tons/year/km2); NOx from 217 to 328 tons/year/district (1.8 – 3.4 tons/year/km2). Similarly, the remaining districts can be received the emission is 164,000 – 653,000 tons of CO/year/district (1,308 – 2,555 tons/year/km2); 5,500 – 7,300 tons of SO2/year/district (17 – 29 tons/year/km2) and 31,000 – 44,000 tons of NOx/year/district (77 – 147 tons/year/km2).

The axial load carrying abilities and the buckling behaviour of Cold-Formed Steel (CFS) Stiffened Built-up Columns (SBC) has been presented in this paper. In total, the results from 8 actual experiments and 64 finite element models in the parametric studies on CFS back-to-back channels built-up screw fastened SBCs with different cross-sections are reported. The specimens were tested with fixed end condition under axial compression. Sections with lip and web stiffeners predominantly failed due to distortional buckling mode whereas all the other sections failed due local or global flexural buckling mode or interaction of local and global modes of failure. The inclusion of intermediate stiffeners and global stiffeners supported in resisting buckling. The results obtained from this study were compared with the estimated load carrying capacities using Direct Strength Method (DSM) design equations. It was found that for built-up SBC members the method of calculating its compression capacity was over-conservative. SBC sections made of lipped channels along with longitudinal stiffeners exhibited highest load carrying ability. Providing stiffeners at the junction of flange and web portions did not radically increase in load carrying ability when compared to sections having stiffeners in the webs and lip portions. SBC sections made of lipped channels also failed in similar buckling phenomenon like in other sections but the plate element local buckling predominantly occurred at the lip portions.

In South Asian countries concrete is mostly used as construction material, especially for low rise structures. Still steel is not predominantly used in high rise structures. Besides, Reinforced Cement Concrete (RCC) and steel structures; composite structures can be built to get maximum benefit of the steel and concrete, as well to produce reliable and economic structures. In this paper comparative study of nine storey hospital RCC and steel building is carried out. For the modelling and analysis of RCC and steel structure ETABs software is used. Comparative study of different parameters like base shear, load carrying capacity, displacement, time period, axial force, and cost is carried out with RCC and steel structures. Final results illustrates that steel structures are more suitable for high rise structures, less time consuming and they are cost effective too.

Corrosion occurs to steel structures due to long life and environmental exposure, which affects the load carrying capacity (LCC) and thus life of structure. Traditional methods of repairing the corroded sections are replacement and attaching other plates to damaged section. So, strengthening steel structure with CFRP laminates is now days a popular technique to regain the lost capacity due to corrosion. In this paper, a fully corroded I beam section is considered for strengthening purpose. Two sample beams of one meter length were taken from the parent beam for experimentation. Two layers of CFRP laminates were used to all sides of beam for strengthening purpose. The model of corroded I-beam was developed in ANSYS software based on average thicknesses of section. Original strength of corroded beam is calculated by using ANSYS and then comparison is done with experimental results. Results show that LCC and yield capacity of strengthened corroded beam is improved using CFRP laminates. Hence, use of CFRP laminates can be used to corroded steel sections for strengthening purpose and it is one of the best way to improve its overall strength and LCC.

This work aims to evaluate the punching shear carrying capacity of flat slabs of reinforced concrete added with different amounts of steel fibers and varying the rectangularity index of columns under symmetrical loading. The addition of steel fiber provide higher load-carrying capacity. However, the column rectangularity index tends to lower that load-carrying capacity for magnitudes beyond 1.5 for the tested slabs. Nine models were tested with dimensions of 1,800 × 1,800 mm and 130 mm height varying the amount of added fiber (0, 50 and 60 kg/m) and the index of rectangularity (1.0, 1.5 e 2.0). From the results, the load carrying capacity, the vertical displacement, and the crack patterns were obtained. In addition, the results were compared with other similar studies and analytical models for steel fiber. The addition of steel fibers showed to be effective in increasing the punching shear load carrying capacity, it leads to a higher number of cracks and higher vertical displacements. Regarding the rectangularity index, for those tested slabs which was below 1.5, the load carrying capacity of punching shear of the slabs increases. However, for slabs above 1.5, it was observed that the punching shear load carrying capacity decreases.

Waffle slabs are lighter in weight than an equivalent solid slab which helps in diminishing the weight with its voids. This study is performed to investigate the behaviour of the waffle slab. Waffle slab types of construction are economical for building where there are long spans, over between 5 m and 6 m with light to moderate live load. It reduces slab weight by reducing amount of concrete. The waffles slab less in dead load and high in load caring capacity. This would allow the structural designer to reduce the size of column, footing and other load bearing elements. For literature review, it is observed with variation in spacing, depth of beam and analytical results of waffle slabare studies. In this project work the waffle slab system with various spacing of grid beams are casted and tested for the load carrying capacity.

This paper discusses an information model of a com-puter aided system of software-algorithmic and information tools for advanced forecasting of the parameters of the technical condition of components and aggregates of a load-carrying vehicleby the results of diagnostics present-ed as hierarchically related sets of the complete set of its components. As components of software-algorithmic and information tools, many of the considered models of load-carrying vehiclesare identified; their components and ag-gregates; parameters of the technical condition of load-carrying vehicles; nominal, current and permissible values of the technical condition parameters without repair; the remaining resource of the technical condition parameter; methods for improving forecasting; the coefficient of curva-ture of the change in the predicted parameter over time; normative and reference information; input operational information; operational calculation/output information; development of control actions; operations for diagnosing units and components of load-carrying vehiclesduring the next maintenance No. 1 and others. This model is applica-ble in the development of a system in the environment of a computer spreadsheet for load-carrying vehiclesthat actu-ally exist on farms.

Solid organic fertilization of soil proves one of the most important factors which contributes to increasing the yielding capacity of farm crops and improving their production qualities. Along with other means of mechanization body machines are used for the mechanized fertilization of soil through distributing fertilizers along the field surface. The paper is aimed at determining and investigating the carrying capacity of body machines used for applying solid organic fertilizers depending on their load-carrying capacity. The research technique lies in the comparative analysis of the determined resultative and factorial characters on the basis of the information obtained from the enterprises wlurh produce body machines. The information was chosen from the catologues of farm machinery and folders of the corresponding enterprises that produce tluse machines. The carrying capacity of machines was determined as the second-by-second advance of fertilizers in mass units (kilograms) to working parts of spreaders through the corresponding calculations; and the processing of harvesting and calculated data was carried out on the principles of the correlation and regression analysis, as wele as with the use of standard computer programs. The volume of statistical sampling amounted to 43 pairs of the investigated characters. The above has made it possible to estaflish. The positive correlation link between the carrying capacity of machines and their load-carrying capacity with the correlation coefficient amounting to 0.647 according to the correlation link of the resultative character on the factorial one, which equals 0.671. To ultimately determine the character of the relation between the investigated characters the authors accomplished the beveling of statistical data related to the carrying capacity of machines depending on their load-carrying capacity in the form of equations with straight line with positive angular coefficient and a number of curved lincar dependences. With iespeet to R2-coefficient the best correlation with experimental data was achieved through their approximation by means of equations of slow increasing step function. Of the investigated change is presented by the equation of the increasing hyperbola (R2=0.820), then according to the hyperbola asymptote with the load-carrying capacity increase of more than 20 tons their carrying capacity can amount to the marginal value of 25 kg/ses. The investigated dependences have to be taken into account when designing body machines used for applying solid organic fertilizers, as well as when using them for soil fertilization under the technological processes of mechanized growing of farm crops.

Various factors are responsible for injuries that occur in the U.S. Army soldiers. In particular, rucksack load carriage equipment influences the stability of the lower extremities and possibly affects gait balance. The objective of this investigation was to assess the gait and local dynamic stability of the lower extremity of five subjects as they performed a simulated rucksack march on a treadmill. The Motek Gait Real-time Interactive Laboratory (GRAIL) was utilized to replicate the environment of the rucksack march. The first walking trial was without a rucksack and the second set was executed with the All-Purpose Lightweight Individual Carrying Equipment (ALICE), an older version of the rucksack, and the third set was executed with the newer rucksack version, Modular Lightweight Load Carrying Equipment (MOLLE). In this experiment, the Inertial Measurement Unit (IMU) system, Dynaport was used to measure the ambulatory data of the subject. This experiment required subjects to walk continuously for 200 seconds with a 20kg rucksack, which simulates the real rucksack march training. To determine the dynamic stability of different load carriage and normal walking condition, Local Dynamic Stability (LDS) was calculated to quantify its stability. The results presented that comparing Maximum Lyapunov Exponent (LyE) of normal walking was significantly lower compared to ALICE (P=0.000007) and MOLLE (P=0.00003), however, between ALICE and MOLLE rucksack walking showed no significant difference (P=0.441). The five subjects showed significantly improved dynamic stability when walking without a rucksack in comparison with wearing the equipment. In conclusion, we discovered wearing a rucksack result in a significant (P

Concrete-Filled Steel Tubular Structures (CFSTSs) have become popular among the structural engineering community due to significantly higher load carrying capacity compared to conventional reinforced-concrete structures. Much research has been conducted on understanding the behavior of CFSTSs under various loading conditions and design theories have been established to predict the load carrying capacities of such structures. However, existing models do not consider the effects of sustained early loads on concrete strength and elastic modulus development of CFSTSs. With the need for rapid construction, CFSTSs may be subjected to loading at an early stage before concrete is fully cured. Such early loading may incur negative effects on strength and elastic modulus development of concrete within the confined environment. This paper propose theoretical models based on the compressive packing model (CPM) to simulate strength and elastic modulus development of early-age concrete under sustained stress. Development of concrete properties at early age is described using Hydration kinetics, and maximum paste thickness in the CPM model is modified using energy conservation to simulate sustained loads. Early concrete strength and the elastic modulus development rules were investigated experimentally for sustained loads. Predictions from the proposed models are compared with conventional models from CEB-FIP Model Code. Results showed that when loaded at a very early stage, a relatively high stress to strength ratio will result in causing damage in concrete. Such damage significantly affects the strength and elastic modulus development. Compared with concrete loaded at 28 days, concrete loaded at early stages showed significant reduction in concrete strength and elastic modulus.

This paper reviews some experimental and numerical results about the hollow reinforced concrete beams (HRCB). Any subtraction in concrete quantity within the structural members without a considerable lack in load carrying capacity represents a common research trend nowadays due to the decrease in sections dimensions, reinforcing steel and lateral inertia forces in severe earthquakes as well as the sustainability gain for the resulting inhibiting of CO2 emission. In addition, the possibility of passing the electrical and mechanical facilities comprises another good feature of such type of structural members. During the traditional beam design process, the tension concrete is considered as strain transfer agent and do not have any role for structural resistance. As a result, longitudinal holes can be made within this area to produce the hollow reinforced concrete beams (HRCB). In this paper some remarkable research works are summarized with the most important conclusions within this field.

The structural stiffness of a tensegrity is dominated not only by the material stiffness, but also by its internal forces. The deployment of tensegrities with member length actuation is investigated with an emphasis on the variation in the structural load-carrying stiffness. The relationship between the driving elongation of members and the structural displacement is established. The analytical incremental expressions for the elastic stiffness matrix and the geometrical stiffness matrix with respect to the driving elongation of members are given. The variation in the load-induced elastic deformation can thus be evaluated for a tensegrity being deployed. A basic equation that satisfies both the equilibrium condition and the load-carrying stiffness constraints is established and used to trace the equilibrium configurations on the deployment path step by step. The solutions for the driving elongation of members are discussed for the objectives of producing the shortest actuation distance and reducing the driving energy, respectively. A numerical strategy is suggested to correct the errors caused by the linear assumptions that are introduced in the derivation of the basic equation. The proposed method is employed to analyse the deployment of an illustrative cantilever tensegrity subjected to load-carrying stiffness constraint, and the results verify its validity. When the objective of reducing the driving energy is adopted, the cantilever tensegrity exhibits an adaptive deformation capability to maintain the constant load-induced deflection at its end joint throughout the deployment process.

The objective of this paper is to analyze the dynamic response of the stiffened plated structures under moving loads with different velocities using the finite element method. The free vibration results as well as the deflection results due to a single moving load are compared with previous studies. A finite element MATLAB code is developed to offer an efficient solution for dynamic analysis of stiffened plated structures under single and multiple moving loads in which various types of stiffener are attached to the plate. Some of the example results have been verified with FEAST (Finite Element Analysis of STructures) software to show the efficacy of the method. The parametric study is carried out by attaching various types of stiffeners in the main load carrying direction to find out the maximum deflections under single and multiple moving loads and also for the moving loads passing in opposite directions on the bridge with different velocities. The central deflection due to moving loads on stiffened plates with fixed/floating transverse frames is also analyzed in this paper.

While there is abundant research information on ordinary concrete beams strengthening or repairing with FRP, relatively little data on the behavior of self-consolidating concrete (SCC) is available. Carbon Fiber Reinforced Polymers laminates (CFRP) was investigated for strengthening and repairing SCC and high strength self compacting concrete (HSSCC) beams subjected to one midpoint load in in order to compared to beams made of normal concrete (NC) and normal high strength self compacting concrete (NHSSCC) at the same conditions respectively. To demonstrate the concept, this paper presents results of a laboratory investigation of 24 beams (150x200x1600 mm) on the behavior of self compacting concrete strengthening and repairing with one layer of CFRP laminate and subjected to one midpoint load, including the effect of using 8 different mixes to study the effect of mix proportions on rapped CFRP beams behavior. Test results showed that the addition of CFRP laminate to the tension surface of the beams demonstrated significantly improvement in stiffness and ultimate load capacity of beams. The response of control and strengthened beams were compared and evaluated by experimental and theoretical calculations. It was observed that ductility indexes of SCC and HSSCC beams were more efficient than NC and NHSC respectively. Load carrying capacity of control, strengthening and repairing self compacting concrete beams was closed to traditional concrete beams (about 90-95%). The paper also highlighted the crack pattern of all cases of beams which indicated more distribution and smaller crack amplitude for strengthened beams with respected to the control beams.

Objective The aim of this review was to determine how exoskeletons could assist Australian Defence Force personnel with manual handling tasks. Background Musculoskeletal injuries due to manual handling are physically damaging to personnel and financially costly to the Australian Defence Force. Exoskeletons may minimize injury risk by supporting, augmenting, and/or amplifying the user’s physical abilities. Exoskeletons are therefore of interest in determining how they could support the unique needs of military manual handling personnel. Method Industrial and military exoskeleton studies from 1990 to 2019 were identified in the literature. This included 67 unique exoskeletons, for which Information about their current state of development was tabulated. Results Exoskeleton support of manual handling tasks is largely through squat/deadlift (lower limb) systems (64%), with the proposed use case for these being load carrying (42%) and 78% of exoskeletons being active. Human–exoskeleton analysis was the most prevalent form of evaluation (68%) with reported reductions in back muscle activation of 15%–54%. Conclusion The high frequency of citations of exoskeletons targeting load carrying reflects the need for devices that can support manual handling workers. Exoskeleton evaluation procedures varied across studies making comparisons difficult. The unique considerations for military applications, such as heavy external loads and load asymmetry, suggest that a significant adaptation to current technology or customized military-specific devices would be required for the introduction of exoskeletons into a military setting. Application Exoskeletons in the literature and their potential to be adapted for application to military manual handling tasks are presented.

This study investigated the ultimate load capacity of assembled system supports by comparing cases with and without bracing members. Supports used as temporary structures are essential to resist the concrete casting load. Current trends encourage the use of system supports to prevent the collapse of supports, which occur frequently. Studies regarding the ultimate behavior of system supports in Korea are fewer than those in other countries. Existing studies have only focused on the behavior of unit members, such as vertical members. However, studies that focused on unit vertical members under axial loading reported difficulty in predicting the ultimate behavior of assembled system supports. Furthermore, the ultimate strength of the system support can be decreased significantly in cases without a bracing member, which occur frequently at actual sites. Therefore, the ultimate behavior of the system support considering actual construction site conditions was investigated through experimental tests, focusing on whether bracing members were installed. Experimental results showed that the load-carrying capacity of a three-story system support without a bracing member was 38.4% that of the system support with full bracing members. In addition, the load-carrying capacity of the three-story system support without bracing members decreased by 41.2% compared with that of a two-story system support without bracing members. This indicates that the installation of bracing members is essential for increasing the ultimate load capacity of system supports, and the number of stories of system supports should be considered to determine their ultimate strength.

This paper numerically studies the behaviour of two adjacent strip footings on unreinforced and reinforced granular bed (RGB) overlying clay having voids. The influence of different parameters such as granular bed thickness, length of reinforcement/s, number of layers of reinforcement, presence of void/s beneath the footing/s in the weak soil, on the behaviour of footings are carried out in this study. It is found that there is a certain optimum spacing between the two adjacent strip footings at which the footing/s carry the maximum load. The voids could be formed in weak soil due to various reasons and the presence of voids may affect the performance of footings. Such voids tend to reduce the load carrying capacity of the footing/s. However, providing a RGB over weak soil can be used as an effective method to maintain the good performance of footings, even when voids could be formed in future.

In this paper, we are study about flat belt conveyer system with different R.P.M. such as 50,100,150,200,250 and 300 R.P.M. In this study, it is also included that the observations the different load carrying capacity (Grams) at different working time (Hours). The flat belt conveyer system is very important for the purpose of the material handling system from one place to other place, which is directly depended on the effective length of belt as 1800 mm. In this system we are used the D.C. motor drive system for the purpose of the loading and unloading condition of metallic hook , which is attached the lower portion of flat belt.

As significant growth of iron production in China in recent decades, plenty of blast furnace slag is generated. Meanwhile, the policies on the natural aggregate exploitation has been getting more restricted as it threats the environmental conditions. There is an alternative solution to the above issues that furnace slag aggregate concrete is filled in middle between double-skin tubular (DST) columns with external stainless steel tubes. This study conducted a series of tests on furnace slag aggregate concrete filled double-skin tubular (CFDST) stub columns under sustained loading condition. The experimental investigations were conducted on circular specimens with furnace slag aggregate replacement ratio of 100%. The hollow ratio of the specimens ranged from 0.5 to 0.75. A total of 8 specimens were tested to capture the behaviours of the creep, shrinkage, ultimate strength before and after 6 months sustained loading. The results indicated that the shrinkage strain of the sandwiched furnace slag aggregate concrete tended to stabilise after 30 days and the creep developed constantly throughout the 180 days of the test. The furnace slag aggregate CFDST specimens with stainless steel tubes have demonstrated well load carrying capacity and ductility under sustained loading. The existing design methods were evaluated on the applicability on the stainless steel-furnace slag aggregate specimens under sustained loading and reasonable predictions were obtained.

Состояние проблемы. Сжатые железобетонные элементы изготавливаются по трем основным технологиям - вибрированием, центрифугированием и виброцентрифугированием. Однако все основные расчетные зависимости для определения их несущей способности выведены, исходя из основного постулата - постоянства и равенства характеристик бетона по сечению, что соответствует действительности лишь в вибрированных колоннах. Результаты. Разработан усовершенствованный нормативный подход к расчету прочности центрифугированных и виброцентрифугированных железобетонных колонн, заключающийся в использовании в расчете интегральных или дифференциальных характеристик бетона. Выводы. Расчет прочности коротких центрально сжатых вибрированных, центрифугированных и виброцентрифугированных колонн по усовершенствованному нормативному подходу дал наилучшие результаты с использованием дифференциальных характеристик бетона, различающихся по сечению. Statement of the problem. Compressed reinforced concrete elements are manufactured according to three main technologies - vibrating, centrifuging and vibrocentrifugation. However, all the main calculated dependences for determining their load-bearing capacity were derived based on the main postulate - the constancy and equality of the characteristics of concrete over the cross section, which corresponds to reality only in vibrated columns. Results. An improved regulatory approach has been developed for calculating the strength of centrifuged and vibrocentrifuged reinforced concrete columns, which involves using the calculation of integral or differential characteristics of concrete. Conclusions. Strength analysis of short centrally compressed vibrated, centrifuged and vibrocentrifuged columns using an improved regulatory approach yielded the best results using differential characteristics of concrete varying in cross section.

Concrete-filled steel tube (CFST) columns are increasingly used in different structures owing to their excellent load carrying capacity provided by the interaction between the concrete core and steel tube. However, there is lack of information on the design and prediction of the behavior of CFST columns with rubberized concrete core when they are exposed to elevated temperature. This paper presents a study on the axial compressive behavior of short CFST columns containing steel fiber and tire rubber particles exposed to elevated temperatures. To this effect, steel fibers were added at two volume fractions of 1% and 1.5% and tire rubber particles were added as fine aggregate at two replacement ratios of 5% and 10% to the concrete core. CFST columns were exposed to four temperatures of 20 (as control), 250, 500 and 750 °C, and then axial compression tests were conducted on them. The experimental test results show that an increase in the exposure temperature to 500 °C does not have a significant influence on the compressive strength of CFST columns, whereas an increased temperature to 750 °C results in a significant decrease (34%) in the compressive strength of the columns. It is also found that an increase in the exposure temperature, steel fiber volume fraction and rubber replacement ratio lead to an increase in the axial and lateral strain corresponding to the compressive strength of CFST columns. It is shown that the predictions of the compressive strength and axial stress–strain relationship by the proposed model are in good agreement with the tests results of both unheated and post-heated CFSTs.

The study presents possible savings resulting from the use of deep-penetration welding processes in the fabrication of welded structures. The study-related tests revealed 80% savings of filler metals and the 50% reduction of welding distortions without compromising the maximum load-carrying capacity of welded joints. The tests involved steel grades S355J2, S460NL, S700MC, S690QL and 450HBW (Hardox) having thicknesses restricted within the range of 8 mm to 20 mm as well as filler metal grades G4Si1 and G69.

Upper-bound estimation of the load-capacity of cold-formed steel sections (TWCFS) with perforations, subjected to axial compression is presented. The estimation is performed on the basis of the Yield Line Analysis ((YLA). TWCFS lipped channel sections with two sets of perforations (on the web and on the flanges) are under investigation. The comparison of experimental results, FE simulation results, European code ultimate strength predictions and upper-bound estimation based on YLA approach is carried out and presented. Some conclusions concerning an applicability of the YLA approach for ultimate strength prediction of perforated TWCFS structural members are derived

Since 1960s, the development of exoskeleton robots have been advancing in the applications such as load carrying, walking endurance, physical assistance and rehabilitation therapy. Rehabilitation therapy in itself is related to walking ability restoration; especially for the elder people. A survey by The United Nations in 2017 revealed increase trend in the number of ageing population. Due to ageing, it may cause weakened limbs, lower limb injuries or disabilities resulting in walking impairment. Elder people suffering from walking impairment will need to undergo walking therapy to recover walking ability. A walking rehabilitation exoskeleton robot can be used for such patients to undergo the therapy by wearing it on their lower body. A lower limb exoskeleton effectiveness for gait recovery assessment in the design stage is not truly explored yet. This can be done by obtaining the simulation model of the lower limb exoskeleton robot structure from its CAD design. The gait pattern tracking response performance of the exoskeleton design to given inputs can then be observed. The lower limb exoskeleton structure is designed using Autodesk Inventor and then imported into SimMechanics. A block diagram of the exoskeleton model is generated, whereby the model is simulated and its response is observed. Given mathematical expression and experimental data inputs, the exoskeleton model with control system is able to track given joint trajectory inputs. The lower limb exoskeleton model shows that the response of its joints to the inputs can replicate human joints behavior during walking for any given stimulus inputs.

Achieving the required price indicators when creating new mobile wheeled vehicles becomes possible due to the use of metallurgical products. The objective of this study is to develop technical solutions for a cabin of a mobile wheeled vehicle by using special steel profiles, tubes, sheet material, stampings, and subunits assembled together to form a load-carrying steel frame; and to study the strength of such cabin frame. A welded construction of a load-carrying steel frame of the mobile wheeled vehicle cabin is proposed, consisting of quadrangular tubes and additional rolled steel sheet elements profiled in several directions. An analytical computer model has been developed to study the design of the load-carrying cabin frame by using finite element analysis. To evaluate the strength properties, calculations in accordance with the regulatory requirements of GOST R ISO 5700–2008 and GOST R ISO 3471–2009 were performed. The results of these calculations have shown that the developed load-carrying steel frame of the cabin provides the necessary flail space for the vehicle operator in accordance with the requirements of the regulatory documents.

The article deals with an analysis of railway masonry arch bridges. Typical attributes of these bridges are pointing loss and backfill. Therefore, the material - masonry - behaviour can be described only by a non-linear stress-strain diagram, mainly because of low or no tensile strength. The load carrying capacity, which is one of the main parameters when assessing the bridge, is a non-linear problem with many inputs, such as properties of backfill and masonry, backfill depth and geometry of the arch. Some of these parameters can be obtained by a diagnostic survey or from archival documentation. Some of these parameters impact the calculation greatly and some negligibly. The identification of key parameters, which must be stated by the diagnostic survey, is the goal of this article.

In this paper, the behaviour of hybrid steel beams having openings in the web has been analytically studied. Hybrid beams are often used when the design requirement is not satisfied by hot rolled sections or homogeneous built-up sections. Typically, the steel grade in flange is higher than the web. The presence of openings in the web tends to result in different modes of failure such as web-post buckling and vierendeel mechanism. This paper attempts to analyse a hybrid steel beam with hexagonal web openings. The modes of failure of such beams are compared to their homogeneous counterparts along with the load carrying capacity for each. Center-to-center spacing of openings is varied as well as the effect of change in depth of openings is observed in this study. A general observation is made for modes of failure which are found to be very similar for homogeneous and hybrid beams. An optimum ratio of spacing and width of opening is determined to be 1.5 for beams having a depth of opening lower than 60% the beam depth. For opening depths larger than 60%, load carrying capacity is drastically reduced. For spacing ratio below 1.5, web-post buckling is pronounced and the beam does not reach its plastic capacity.

Continuous curvilinear variable stiffness (CCVS) is presented as a novel solution to improve the load carrying capacity of a fuselage panel with a cutout. The CCVS technique allows for the tow path...

Fatigue behavior of corroded non-load-carrying fillet welded joints exposed to atmosphere in Nanjing for 1-year which were made of bridge weathering steel Q345qNH was explored in this paper. Fatigue tests were conducted on 8 specimens which were under 8 stress ranges, fitted S-N curve and lower bound of 95% survival probability were established. It was found that fatigue strength dropped by 26.2% after 1-year exposure compared to uncorroded specimens, the design S-N curve for non-load-carrying fillet welded joint in Eurocode 3 is still satisfactory for fatigue assessment of this batch of specimens. Fractography analysis revealed that fatigue cracks always originated from multiple corrosion pits, geometries of corrosion pits were quantified by surface morphology analysis. Numerical simulation of mixed-mode fatigue crack propagation was conducted, it is found that taking the geometry of the deepest pit as the equivalent initial crack and orienting the crack in the direction normal to the maximum tensile stress plane could predict fatigue lives safely and satisfactorily. The research provides reference for design and fatigue assessment of uncoated weathering steel bridges.

Load-carrying exoskeletons need to cope with load variations, outside disturbances, and other uncertainties. This paper proposes an adaptive trajectory tracking control scheme for the load-carrying exoskeleton. The method is mainly composed of a computed torque controller and a fuzzy cerebellar model articulation controller. The fuzzy cerebellar model articulation controller is used to approximate model inaccuracies and load variations, and the computed torque controller deals with tracking errors. Simulations of an exoskeleton in squatting movements with model parameter changes and load variations are carried out, respectively. The results show a precise tracking response and high uncertainties toleration of the proposed method.