Maximum Load-carrying Capacity Research Articles

Analysis of Pollutant Load Carrying Capacity of the River Tapi Using QUAL2Kw for Surat City

River Tapi is the prime water body for Surat city, Gujarat, India. On a long stretch of 22.39 km in Surat city (Kamrej to Causeway) of the Tapi river, there are many identified and non-identified discharge points available. Excessive discharge from these points restricts the efficiency of the self-purification process which ultimately degrades the river water quality. In this paper, an attempt has been made to estimate the pollutant load-carrying capacity at different segments of the river Tapi using the QUAL2Kw tool. The study has been undertaken with different scenarios: First, the QUAL2Kw model was trained with available river water quality and hydraulic data of the Tapi river in which the complete river segment was divided into 21 reaches. The model was calibrated and validated with the actual concentrations of the pollutants entering. In the second phase, all the point source, non-point source, and headwater characteristics were considered and the pollutant load-carrying capacity of the river in terms of BOD, ISS, and N-nitrate was found. In the third phase, all the sources of pollutants entering the river have been removed and only headwater characteristics were considered for the study. The results indicate that reach no. 21 (21.23ºN, 72.82ºE) has the maximum load-carrying capacity of Biochemical Oxygen Demand (BOD) up to 2057.7 kg/day, Inorganic Suspended Solids (ISS) up to 85633.8 kg/day, and Nitrate (NO3) up to 31688.8 kg/day. However, reach no. 4 has the minimum load carrying capacity of BOD up to 1088.1 kg/day, reach 8 carries a minimum of ISS 205341.6 kg/day and NO3 10215.57 kg/day.

Performance of Sustainable Insulated Wall Panels with Geopolymer Concrete.

The increase in the population creates an increased demand for construction activities with eco-friendly, sustainable, and high-performance materials. Insulated concrete form (ICF) is an emerging technology that satisfies the sustainability demands of the construction sector. ICF is a composite material (a combination of expanded polystyrene (EPS) and geopolymer concrete (GPC)) that enhances the performance of concrete (such as thermal insulation and mechanical properties). To investigate the axial strength performance, five different types of prototypes were created and tested. Type I (without reinforcement): (a) hollow EPS without concrete, (b) alternative cells of EPS filled with concrete, (c) and all the cells of EPS filled with concrete; and Type II (with reinforcement): (d) alternative cells of EPS filled with concrete; (e) and all the cells of EPS filled with concrete. Amongst all the five prototypes, two grades of GPC were employed. M15 and M20 grades are used to examine the effectiveness in terms of cost. For comparing the test results, a reference masonry unit was constructed with conventional clay bricks. The main aim of the investigation is to examine the physical and mechanical performance of sandwich-type ICFs. The presence of polystyrene in ICF changes the failure pattern from brittle to ductile. The result from the study reveals that the Type II prototype, i.e., the specimen with all the cells of EPS filled with concrete and reinforcement, possesses a maximum load-carrying capacity greater than the reference masonry unit. Therefore, the proposed ICF is recommended to replace the conventional load-bearing system and non-load-bearing walls.

The Effect of Rectangular Grooves on the Lubrication Mechanism in an Inclined Slider Bearing

This research aims to study the effect of rectangular grooves on the lubrication mechanism in an inclined slider bearing. Reynolds' equation was used in the theory part to calculate the pressure gradient in a one-dimensional fluid film. The tilted sliding bearing compared the practical results, where the researcher manufactured and developed the device by adding pressure sensors along with the pad. These sensors will give accurate readings because they will read the pressure directly from the bottom of the pads without manometer tubes. Four pads were manufactured, one without grooves and three with rectangular grooves, varying slot widths (3, 5, 8mm), and a depth of 2mm. This study examined various variables: sliding velocities, pad inclination values, and oil temperatures. The conclusions indicated that the flat model is significantly superior to the groove’s models. One significant finding for grooved models is that as the inclination increases, the maximum load capacity approaches the pad's center, allowing grooved models to be used in applications requiring less load and weight. The maximum load-carrying capacity of flat and grooved models was in the film ratio (K) = 2–2.5. In contrast, the load capacity of the flat model was greater than that of the groove model by percentages of 0.5%, 4.27%, and 14.66%, respectively. Moreover, the flat model's coefficient of friction is lower than the coefficient of friction of the groove models, with percentages of 0.38%, 4.63%, and 17.37%, respectively.

Multi-objective optimization of nonlinear inelastic steel trusses with continuous design variables using NSGA-II

Thank to the rapid development of computer technology, optimization design has been increasingly widely applied in all areas of life. In structural optimization, due to the variety and even contradiction between the desired goals of design engineers, multi-objective optimization attracts more and more attention from scientists. In this paper, the author presents the multi-objective optimization design problem for steel truss with two basic objectives: the truss mass and the horizontal displacement of the top of the truss is minimized. The design variables are the cross-sectional areas of the structure that are in the defined ranges. Direct analysis is used to capture the nonlinear behavior as well as calculate the maximum load-carrying capacity of the structure. The optimization problem set up above is solved by NSGA-II (Non-dominated sorting GA-II) algorithm. A 47-bar planar truss is studied to illustrate the optimal design problem. The results show that the NSGA-II algorithm is very effective in solving the given optimization problem.

Optimum boundaries for maximum load-carrying capacity in water-lubricated composite journal bearings incorporating turbulences and inertial effects based on elastohydrodynamic analysis

Abstract The application of polymer-based composite materials as bearing liner materials in eco-friendly water lubrication has received considerable attention owing to their superior tribological behaviors, corrosion resistance, and high damping characteristics, and their design flexibility can improve the bearing performances in response to the distribution of lubricant film pressure based on the regulation of elastic constants. However, the low viscosity and high density of water essentially cause thin-filmed lubrication accompanied by a low load-carrying capacity. Particularly, a high rotational speed enhancing the wedge effect induces turbulence and considerable inertial effect. Moreover, substantial elastic deformation of the composite bearing liners alters the formation of the lubricant film. In this study, we analyze a water-lubricated composite journal bearing system incorporating the turbulence, inertial effect, and elastic deformation of the bearing liner. Reynolds equation was modified considering the turbulence and inertial effect. The elastic deformation of the composite bearing liner was determined by solving the constitutive equation. The Reynolds equation and the constitutive equation were solved via the finite difference method and finite element method, respectively. In addition, the analytical relation for the elastic deformation was derived that suitably eliminated the requirement of solving the constitutive equation. With the introduction of the primary parameters, Sommerfeld number, Reynolds number, and deformation coefficient, the relation of the normalized minimum film thickness with respect to the parameters was modeled based on the Gaussian regression model. Accordingly, we proposed the new optimal maximum load-carrying capacity boundaries that narrowed down the operating region compared to conventional boundaries.

Comparative Study on the Behavior of Reinforced Concrete Beam Retrofitted with CFRP Strengthening Techniques.

Lateral reinforcement has a significant impact on the strength and ductility of concrete. Extra confinement is provided in this project by carbon fiber reinforced polymer (CFRP) sheets wrapped around the outside of reinforced concrete (RC) beams. To determine the failure criteria and maximum load-carrying capacity of beams, numerous specimens were cast and tested in a flexural testing machine. This paper presents the results of an experimental investigation of functionally damaged reinforced concrete beams repaired in flexure with CFRP sheets. The most essential variable in this study is the CFRP sheet scheme, and seven different strengthening schemes (B1 to B7) were explored in the experimental program. In conclusion, the findings of the study showed that flexural retrofitting of reinforced concrete beams with CFRP sheets is functionally effective, with restored strength and stiffness values roughly equivalent to or greater than those of the control beam (CB1). The efficiency of the flexural retrofitting mechanism appears to vary depending on the layout of the CFRP sheet. Steel rupture and concrete crushing were shown to be the most common failure modes in the investigation, causing CFRP sheets to break in retrofitted beams.

Effect of Fiber Wrapping on Bending Behavior of Reinforced Concrete Filled Pultruded GFRP Composite Hybrid Beams.

The application of pultruded fiber reinforced polymer (FRP) composites in civil engineering is increasing as a high-performance structural element or reinforcing material for rehabilitation purposes. The advantageous aspects of the pultrusion production technique and the weaknesses arising from the 0° fiber orientation in the drawing direction should be considered. In this direction, it is thought that the structural performance of the profiles produced by the pultrusion technique can be increased with 90° windings by using different fiber types. This paper presents experimental studies on the effect of FRP composite wrapping on the flexure performance of reinforced concrete (RC) filled pultruded glass-FRP (GFRP) profile hybrid beams with damage analysis. The hybrid beams are wrapped fully and partially with Glass fiber reinforced polymer (GFRP) and carbon fiber reinforced polymer (CFRP) composites. Hybrid beam specimens with 0° to 90° fiber orientations were tested under three- and four-point bending loads. Based on the experimental load–displacement relationship results, initial stiffness, ductility, and energy dissipation capacity were compared. The experimental findings revealed that the maximum load-carrying capacities of beams produced with pultrude profiles increased by 24% with glass wrapping and 64.4% with carbon wrapping due to the change in the damages. A detailed damage analysis is provided. Similarly, significant increases were observed in structural performance ratios such as initial stiffness and ductility ratio.

Performance analysis of textured journal bearing operating with and without nanoparticles in the lubricant

PurposeThis study aims to investigate the performance improvement of journal bearing by applying the arc-shaped textures on various regions of bearing expressly full, second half and pressure increasing regions operating with and without nanoparticles in the lubricant.Design/methodology/approachThe Reynolds equation is solved numerically by using the finite element method to obtain static performance parameters such as load-carrying capacity (LCC) and coefficient of friction (COF), which are then compared with untextured bearing at eccentricity ratios of 0.2 to 0.8. Aluminum oxide (Al2O3) and copper oxide (CuO) nanoparticles additives are used, and viscosity variation due to the addition of additives in the base lubricant is computed for considering the range of temperatures 50 to 90°C at a weight fraction of 0.1 to 0.5% by using an experimentally validated regression model.FindingsThe results indicate that the maximum LCC and the lower COF are found in the pressure-increasing region. A maximum increase of 34.42% is observed in the pressure-increasing region without nanoparticles, and furthermore, with the addition of Al2O3 and CuO nanoparticles in lubricants in the same region, the LCC increased to 21 and 24%, respectively.Originality/valueDesigners should use optimal parameters from the present work to achieve high bearing performance.

Seismic performance of glulam timber post and beam structures with and without light frame timber shear wall infill

Timber post and beam structure is typical frame construction with a simple structural system and clear force transmission path. This work studies the seismic performance of glued-laminated timber (glulam) post and beam structures under cyclic loading, as well as the effect of light frame timber shear walls on their seismic performance. Experimental investigation on two types of full-scale glulam post and beam structures was carried out to compare the failure modes, mechanical properties, and energy dissipation. According to the test results, simplified models whose nonlinearity was assumed to be concentrated plasticity in the springs were developed. The comparison between test data and model prediction has a good agreement in terms of evaluation from backbone curves and strength degradation ratio. This calibrated model was then adopted as a benchmark model for further parametric analysis. Eight different configurations considering various aspect ratios were modeled to assess the influence of elastic stiffness and the maximum load-carrying capacity using the pushover analysis. The test investigation and numerical analysis of the glulam post and beam structures with and without light frame timber shear walls help comprehensively understand the seismic performance, providing some valuable guidance for further studies and structural design in engineering practice.

Unified Truss-Arch Model for the Analysis of Bending-Shear Interaction in Reinforced Concrete Members

The compatibility strut-and-tie method (C-STM) is a well-established nonlinear modeling tool to efficiently and accurately predict the overall load–deformation response of shear-critical RC members subjected to combined bending and shear. Such a high-performance tool, however, is computationally demanding. In this paper, a simplified limit analysis model based on C-STM is presented to predict the load-carrying capacity of RC beams. Amenable for hand methods of analysis, the approach is called the truss-arch model unified (TAMU). The TAMU approach accounts for the failure mechanism of the diagonal concrete strut that is softened because of the transverse tensile strain. Instead of providing overall force–deformation behavior, this model focuses on evaluating the ultimate load-carrying capacity by assuming the failure mechanism occurs when the principal diagonal strut reaches its softened strength in shear-critical beams. An explicit equation for the principal strain ratio is derived to evaluate the softened concrete strength and is used to develop formulas for the ultimate load-carrying capacity. The validity of the formulas is verified through a comparison of the predicted ultimate load-carrying capacities with maximum measured strengths from previous experimental results on large-scale physical tests representing bridge piers. The TAMU approach is then compared with other code-based strength analysis methods and shows better predictions of the maximum load-carrying capacity.

Anchorage performance of a modified cable anchor subjected to different joint opening conditions

In tunnelling engineering, the cable anchor is usually used to reinforce the surrounding rock mass. Site observation shows that the cable anchor may be subjected to different joint opening conditions. However, little study has been launched to study the influence of the joint opening on the anchorage performance of cable anchors. This paper conducted the laboratory Short Encapsulation Pulling Test (SEPT) to study the anchorage performance of a modified cable anchor subjected to different joint opening conditions. During the test, the joint opening was simulated with the bearing plate whose central diameter was different. The results showed that when the joint opening size increases, the maximum load-carrying capacity of cable anchors decreases. This was observed under both unconfined and confined boundary conditions. Moreover, under the confined condition, there was a threshold for the joint opening size. Once the joint opening size was beyond that threshold, further increasing the joint opening size had marginal effect on the capacity of cable anchors. Additionally, under the confined condition, the maximum load-carrying capacity of cable anchors was apparently higher. Furthermore, under the confined condition, cable anchors showed apparent residual load-carrying capacity in the post-failure stage. By contrast, under the unconfined condition, after the peak, the load-carrying capacity of cable anchors dropped dramatically. This leaded to negligible residual load-carrying capacity.

Computationally aware estimation of ultimate strength reduction of stiffened panels caused by welding residual stress: From finite element to data-driven methods

Ultimate limit state (ULS) assessment examines the maximum load-carrying capacity of structures considering inelastic buckling failure. Contrary to the traditional allowable stress principle which is mainly based on experiences, the ULS assessment focuses on explicitly evaluating the structural safety margin and thus enables a consistent level of safety/risk between conventional and novel structural designs. Modern structures are usually designed as a network of plates and stiffeners (e.g., ship structures, offshore and onshore wind turbine, and land-based bridge) joined by welding which induces a residual stress field. Hence, predicting the ultimate strength reduction of stiffened panels caused by welding residual stress is a crucial problem addressed by many scholars with different approaches, among which the Nonlinear Finite Element Method (NLFEM) is the prevailing approach within the community of structural engineering. Unfortunately, the NLFEM has a high computational requirement which prevents its use in the design, appraisal, and optimisation phases of stiffened panels. To well approximate the nonlinear finite element method, a data-driven method is proposed in this paper, with a functional which is computationally expensive to build but computationally inexpensive to use allowing its application at design stage. Results obtained in different (i.e., interpolation and extrapolation) scenarios using data generated by a state-of-the-art NLFEM on a series of stiffened panels will support the proposed method.

Structural performance evaluation of UHPC/conventional concrete cast on new Y-shape FRP stay-in-place formwork for concrete bridge decks

Overthe pastfewyears, there has been a rise in the use of Stay-In-Place (SIP) structural formworks made of fibre reinforced polymer (FRP). This study investigates the performance of decks made of FRP SIP structural formworks with an improved configuration using conventional and ultra-high performance concrete under static loadings. The proposed new composite deck consisted of a glass fibre reinforced polymer plate stiffened with Y-shape ribs for resisting tensile and shear stresses while reinforcements was placed on the compressive side of the deck. The new composite deck was compared with conventional reinforced concrete solid decks and a composite deck consisting of square hollow section (SHS) stiffeners. Results showed that the deck made of Y-shape stiffeners failed in punching shear, and the use of Y-shape stiffeners significantly enhanced the ultimate strength and shear capacity of the proposed deck. It was also concluded that the voids in the concrete deck with SHS stiffeners resulted in lightweight structures but had a negative influence on the ultimate strength of the deck cast on FRP SIP formwork. Increasing the concrete strength from 34 MPa to 140 MPa resulted in a 71% enhancement in the maximum load-carrying capacity but did not considerably influence their stiffness.

Investigation of mechanical properties of dual-fiber reinforcement in polymer composite

Nowadays, the demand for fiber-based composites increases continuously compared to conventional materials because of their excellent mechanical properties. Synthetic fibers have specific advantages over natural fibers. It includes strength to weight ratio, durability, wrinkle resistance, and the ability to absorb moisture is less. However, the synthetic material having a few demerits also. To overcome the drawbacks of the synthetic fiber-based composite, an attempt is made to fabricate the hybrid composite specimen to obtain the combined benefits of the synthetic and natural fiber-based composites. The potential applications of the hybrid composites are aerospace, marine, and industrial structural applications. The composite specimen has been fabricated by using different natural and synthetic fibers, namely, Abaca (A), Hemp (H), Kevlar (K), and Glass (G). The three different hybrid composite specimens have been fabricated, each consisting of 5 layers are as follows, 1) the first and last layers of the specimen are Kevlar, and the remaining layers are Abaca fibers, 2) the first and last layers are Glass, and remaining layers are Hemp fibers, 3) first and the last layer is Glass, and remaining layers are Abaca fibers. The experimental results of the Glass/Hemp based composite have been compared with the simulation results. A good agreement has been found between the experimental and the simulation results. The Kevlar/Abaca composite displays a maximum load-carrying capacity in tensile, flexural, and impact is 5600 N, 86 kgf, and 3.625 J, respectively, followed by the Glass/Hemp and Glass/Abaca composites. It is due to the load being transferred in the following order during tests, which is as follows: matrix, natural fibers, and synthetic fibers. The displacement corresponds to load, which also increases during tests due to the percentage of elongation of the fibers. The interfacial bonding between the matrix and the fiber is also responsible for better results.

Study of Tensile Strength of Glass Epoxy Laminates with Varied Open Hole Diameter

Composite materials such as fiber reinforced plastics are massively used in engineering due to their high strength to weight ratio when compared to the other conventional materials. Due to its high effectiveness, it has been applied in the aerospace and defence industry, automotive industry, civil, marine platforms and systems and sports equipment. The holes in the composites are the main cause for the structural failure due to the stress concentration observed in the components whilst loading. It is important to investigate the effect of holes on the properties of the structural components. The tensile strength of glass fiber reinforced plastic was investigated with respect to ASTM D3039 with the loading rate of 2 mm/min. The samples were made by vacuum assisted resin transfer infusion method (VARTM) and the diameter of centric holes considered are 4mm, 6mm, 8mm and 10mm. The results are analysed to understand the damage criteria that caused the structural failure. When compared with specimen without a hole and specimen with a hole of 10 mm diameter, the maximum load-carrying capacity of the specimen was reduced by 47.9%. All the specimens were subjected to the scanning electron microscope (SEM) to investigate the failure.

Experimental Study on Bonding CFRP to Fiber Concrete Beam Considering the Effect of using Nanographene Oxide in Improving the Mechanical Properties of Polyamine Resin

This research examined the effect of nanographene oxide in enhancing the mechanical properties of polyamine resin for better adhesion of carbon-fiber-reinforced polymer (CFRP) to a fiber-reinforced concrete beam. To this purpose, 33 fiber-reinforced concrete beams retrofitted with CFRP of lengths 50 cm, 35 cm, and 20 cm and widths 3 cm, 6 cm, and 10 cm were experimentally studied. Graphene oxide weight percentages of 1, 2, and 3 percent were considered, and the corresponding cases were compared with the case of a retrofitted beam without graphene oxide. According to the results of experiments on 12 of the beams, as the nanomaterial in the adhesive increases from 1 to 2 and 3%, the values of maximum load-carrying capacity, maximum mid-span deflection, beam stiffness, and beam toughness exhibited 46,19, 27, and 5 %, respectively, relative to the case of the beam reinforced with CFRP and without graphene oxide. Subsequently, given the close results of the beams reinforced with 2 and 3% graphene oxide. The 2% graphene oxide was used in the rest of the samples to investigate the effect changes in the number of layers, length, and width of the CFRP on the mechanical properties of the concrete beam. The results indicated that an increase in the number of layers, length, and width of CFRP results in an increase in the load-carrying capacity and deformability of the fiber-reinforced concrete beam

The Effect of Geotextile Layers and Configuration on Soil Bearing Capacity

The term "reinforced soil" refers to a composite material with high tensile-strength components that enhance the soil's tensile strength. One of the most common kinds of geosynthetic fabric utilized for soil reinforcement is geotextiles. This article investigates woven geotextile's potential benefits in enhancing the maximum load-carrying capacity of footings resting upon silty sand soil. The foundation was constructed of a 10 mm thick strong carbon steel plate of 100 mm×100 mm. The factors examined in this research were the first geotextile layer's depth, the geotextile layer's width, the number of layers of reinforcing material, and the vertical spacing between geotextile layers. The impact of geotextile strengthening configurations on the load-carrying capacity of strengthened soil foundations was also studied. The results of the experiments indicated that geotextile reinforced soil could help to grow the soil bearing capacity. The testing findings revealed that the system with three geotextile layers, 0.25B vertical distance among geotextile layers, and a geotextile width of 5B, B denotes the plate's width, achieves the most significant bearing capacity. The test findings also revealed that the reinforcement configuration greatly impacted the reinforced silty sand on the foundation's behavior.

Characterisation of Cu–Al alloy lap joint using TIG Welding

It is difficult to join dissimilar material which has different thermal and mechanical properties using conventional arc welding, which is prone to the formation of intermetallic compounds (IMCs). In the present work pure copper (Cu) and aluminium (Al) alloy (Al-6061) is lap joined by conventional TIG Welding. At optimal operating condition, a successful weld is achieved as observed from mechanical testing. The metallurgical properties of joints are investigated by Back Scattered Electron (BSE) image, spot Energy Dispersive X-ray Spectroscopy (EDS) and line EDS. IMCs layers formed for joints varied from 9 μm to 80 μm thickness obtained at different welding parameters. Two different layers of IMCs are formed at the interface and the failure occurred near the copper side of the joint. The mechanical property is investigated by tensile shear test, and the average maximum load-carrying capacity found 1876 N, which is comparable to other non-conventional welding processes.

Health monitoring of steel box girder bridges using non-contact sensors

This study investigates the behavior of simple and continuous span steel box girder bridges after various damage scenarios, including bracing failure and girder fracture, and develops a non-contact bridge health monitoring technique based on the bridge dynamic responses. A series of field tests were conducted to study the feasibility of using non-contact sensors to capture the bridge dynamic responses. Moreover, detailed finite element models of the bridges were developed and validated using the field test and available experimental test results and were used to investigate the bridge failure mechanisms, maximum load-carrying capacity, alternative load paths, and dynamic responses. The bridge dynamic analysis after damage showed that bridge frequencies are sufficiently sensitive for identifying partial or full-depth girder fracture in the simple span bridges. However, these significant damages may cause very small changes in the natural frequencies of continuous span bridges. The results show a significant change in the mode shapes after damage in both simple and continuous span bridges. The mode shapes are sensitive enough to detect damage at the inflicted locations, in most cases with better resolution when compared to the frequency changes. The comparison of the intact and damaged bridge mode shapes indicates that damage at different locations along the bridge has different amplitude changes in the mode shape that could be used to localize the damage. Moreover, the analyses show that either the individual modal sensitivities or combined sensitivities are indicative for most locations throughout the span. The results also indicate a clear pattern of changes in the frequency and mode shape for each damage scenario that can be used to detect the damage type, severity, and location along the bridge.

How much to carry? Implications of maximum load carrying capacity for prey use of urban and rural Northern Goshawks Accipiter gentilis

ABSTRACT Capsule: Compared to their rural counterparts, urban Northern Goshawks Accipiter gentilis potentially maximize their energy delivery to the nest by exploiting heavier prey species close to their maximum carrying capacity. Aims: We aimed to assess prey use of a raptor species with distinct reversed sexual size dimorphism from a perspective of physical limitations during foraging and the transportation of prey. Methods: We estimated the theoretical maximum load carrying capacity (MLCC) of fully developed Northern Goshawks based on their flight muscle mass. Additionally, we collected data on the breeding season diet of Northern Goshawks in urban and rural habitats in Germany. By linking MLCC estimates to the diet we explained the relevance of prey size from a viewpoint of load carrying capacity. Results: Estimates for the mean (± sd) additional portable loads were 684 g (± 237) for males and 971 g (± 235) for females, accounting for 96% and 84% of their body mass, respectively. Overall prey weight averaged higher for urban areas compared to rural ones, while the majority of prey items were between 200 and 500 g and below the estimated MLCC of both sexes, with the exception of single heavy species. Results suggest that prey use of Northern Goshawks during the breeding season is barely limited by prey transportability, since both sexes are physically capable of carrying the majority of prey species to their nest. Conclusions: Urban Northern Goshawks can exploit heavier, available prey species compared to their rural counterparts, allowing them to hunt larger prey closer to their MLCC. Ultimately, by maximizing their energy delivery to the nest, this presumably constitutes one key factor why Goshawks successfully colonized European cities. This study is the first to link estimates of physical limitations in prey transportation for a free-living raptor species to its prey composition in the light of colonizing urban environments.