Inflatable Structures Research Articles

From a Deployable Soft Mechanism Inspired by a Nemertea Proboscis to a Robotic Blood Vessel Mechanism

In this project, we aim to establish a design theory as well as implementation methods for deformable robot mechanisms that can branch and change in shape, structure, and stiffness. As the first step in our research on this project, we present an initial prototype of a branched torus mechanism that uses an inflatable structure inspired by a nemertea proboscis. We develop a basic mechanical model of this proboscis structure, and we confirm the basic performance and effective functionality of the configuration experimentally using a real prototype, specifically, a deployable torus mechanism and a retractable torus mechanism with an incompressible fluid. In addition, as an expanded concept from the branched torus mechanism, robotic blood vessels that can have an active self-healing function are prototyped, and the basic performance of the actual prototype is confirmed through experiments.

Wind tunnel tests of an inflated membrane structure. Two study cases: with and without end-walls

The use of textile membranes in architecture and civil engineering has increased rapidly in the last decades. Membrane structures are lightweight, economic structures with unique shapes. At the same time, their structural analysis is particular compared to the analysis of conventional structures. The form-finding procedure, the large displacements of the structures, and the special properties of the composite material all require unique tools. The wind analysis of membrane structures is one of the most challenging parts of the design because the design codes do not provide the pressure coefficients of the doubly curved shapes of membrane structures. The main scope of the present research was to determine the mean pressure coefficient fields over an inflated membrane structure by wind tunnel experiments. The structure, composed of six inflated circular arches, was analyzed with and without end-walls for three wind directions. The equilibrium shape of the inflated structure was determined with the Dynamic Relaxation Method. During the numerical form-finding procedure, the orthotropic behavior of the membrane material and the warp and fill directions of the textile fibers were also considered. Based on the numerically determined equilibrium shape of the inflated structure, a model was made using a 3D printer. The flow around the model according to three wind directions was analyzed in an open-circuit wind tunnel. The pressures were measured in 102 external and 102 internal points of the inflated arches and 27 points on each end-wall. In this paper, the experimentally determined pressure coefficient fields for different wind directions are presented and compared for the open (without end-walls) and closed (with endwalls) cases. The thoroughly introduced experimental results can be used during the structural analysis of future inflated structures with similar shapes.

Development of a miniature dynamic stiffness measurement prototype toward structural health monitoring of space inflatable structures

Inflatable structures are increasingly used in aerospace engineering. However, the space survivability and durability of such structures are of particular concern due to material aging in space environment and unexpected external impact threats. Thus, it is very urgent to in-situ monitor and assess structural health condition for space inflatable structures. Since inflatable structures are often lightweight, large-sized and flexible, their low-frequency vibration response contains much information about structural health condition. To facilitate in-situ structural health monitoring of space inflatable structures, this paper developed a miniature low-frequency dynamic stiffness measurement prototype. The prototype is capable of generating two channels of swept-sine excitation signals, and concurrently acquiring six channels of response signals. Recorded data is communicated and downlinked from the host spacecraft to the ground, and then the dynamic stiffness is derived to determine structural health condition. To validate the developed prototype, two simulated inflatable space structures are fabricated and tested, including an inflatable boom and an inflatable torus, and then Macro-Fiber Composite transducers are attached on two specimens as actuators and sensors in tests. Experimental studies show that the prototype functions well and the outputted results are consistent with that measured by large-bulked commercial ground devices. Additionally, the multi-channel functionality of the prototype is verified by carrying out the multi-input multi-output test. In summary, the prototype features small size, light weight, and low power consumption, which has the potential for future space applications.

Toward on-orbit structural health monitoring of inflatablestructures using electromechanical impedance method

Abstract Inflatable structures are promising candidates for a wide range of aerospace vehicles due to their volume/weight savings, high storage rate, low cost, and easy deployment. However, space survivability is a major concern for such structures. Therefore, structural health monitoring (SHM) of inflatable structures has been increasingly studied. Electromechanical impedance (EMI) method is one of the most-popular SHM methods, which can promptly and accurately identify early structural damage. Nevertheless, the necessary of using bulky, expensive and high-power commercial impedance analyzer hampers electromechanical impedance method from being used in-situ and online. In recent years, several miniature impedance measurement devices have been developed for practical applications. However, the aerospace application of such devices is still absence. In this paper, a miniature integrated impedance measurement printed circuit board (PCB) prototype toward on-orbit SHM of inflatable structures is developed. The proposed PCB prototype consists of impedance measurement module, in which the AD5933 chip and the ADG708 chip were adopted to achieve impedance signals. In this case, the PCB prototype can effectively measure the electrical impedance of up to six channels of the piezoelectric transducers at 0.2 ∼ 2V excitation voltage in the frequency range of 10 ∼ 100kHz. Moreover, an inflatable boom was taken as the inspected structure, and a PZT-5H was used as the piezoelectric transducer for experimental validation. The results demonstrate that the proposed PCB prototype works functionally and can accurately quantify the simulated damage on the inflatable boom. In addition, it is found that the miniature integrated impedance measurement PCB prototype developed in this paper has the advantages of low bulk and less weight, which can be further enhanced to satisfy the demands of on-orbit SHM of inflatable structures.

Instantaneous optimal control of inflatable folded structures

The inflatable folded membrane structure is mainly made of flexible materials, so it has the advantages of simple structure, high folding efficiency, small launch volume, light weight, low production cost, and high reliable, and it has broad application prospects in large space structures such as space antennas, solar panels. In order to overcome the shortcoming that the traditional constant rate inflation cannot take into account the folded structure development time and stability at the same time, this paper proposes a method of variable inflation rate, which combines the inflation rate with the optimal control, so that the folded structure can deploy quickly and stably. The paper uses extended position-based dynamics method (XPBD) and control volume (CV) method to establish the inflatable folded membrane structure simulation system, and derive its instantaneous optimal control expression with inflation rate as control variable. The simulation of the four-fold tube and the comparison with the constant inflation rate show that the present method is more stable and less kinetic energy than the fast inflation rate, and takes less time than the slow inflation rate. To prove the effectiveness of the proposed control algorithm for complex folded inflatable structure, the paper uses origami to design a sunshield model and simulate the deployment process.

A review on specialty elastomers based potential inflatable structures and applications

With the escalation in continuous human curiosity, massive research work is going on in the field of inflatable structures and inflatable systems. These inflatable structures offer a great advantage for the building of emergency air shelters for civilian and military, industrial fuel and gas storage tanks, life rafts, lifeboats, etc. Even, more advanced inflatables like hull structure for lighter-than-air systems (LTA) and inflated radomes are employed in the defence sector. The advantage of inflatable structures lies on their excellent mechanical strength, lightweight, durability and they can be stored in a small volume. Specialty elastomers play an important role in developing inflatable structures because of their excellent properties towards weather resistance, UV and ozone resistance, stability against aging, and oxidation. In addition, they show good gas and vapour barrier properties. In the beginning of this review article, the structure and properties of specialty elastomers selected in this study have been discussed and then the gas transport mechanism through polymeric material is described. In the last part, the development of diverse types of inflatable systems used in industry, defence, and marine applications have been highlighted. More attention is given to the advanced application of inflatables in the defence sector. Throughout this review work, various literature and published work related to specialty elastomers application in inflatable systems have been reviewed. The main emphasis of this study is on the structure, properties and application of specialty elastomers in the advancement of inflatable structures.

Development of a range of motion device for ankle joints and its operation test

We have developed a passive range of motion (ROM) exercise device for the ankle joints. We applied a pneumatic soft actuator as the drive source. Since the soft actuator has an inflatable structure using flexible materials, it operates with compressed air. In this device, the ankle joint is moved passively by pressing the toes and heels with the actuator. In addition to plantarflexion and dorsiflexion, the device aims to provide supination and pronation that existing equipment cannot provide. In this research, in order to subjectively evaluate the performance of the prototype device, we conducted an operation test on 13 healthy adults.

Применение мягких гидротехнических сооружений рукавного типа при создании пожарных водоёмов и водохранилищ

Purpose. The article presents the results of theoretical and experimental studies of shear stability and hydrodynamic characteristics when interacting with water flow from hose-type soft filled waterworks. Structures of this type are applied to improve hydrological and track conditions, to construct temporary water supply reservoirs, booms for oil spills prevention. The research is aimed at determining calculated dependencies to justify parameters of hose-type filled structures when they are used as dikes and protection structures. Methods. Theoretical method has been used to obtain calculated dependences of structure shear stability. Hydrodynamic characteristics during hose structures interaction with water flow have been determined experimentally on models using similarity theory. Findings. Technique for calculating structure shear stability has been developed. Dependence has been obtained to determine stability factor, which allows setting required values for hose structures and blanket length to achieve stability factor standard value, depending on generated pressure together with soil and shell material frictional properties. Determining factors of interaction process between soft cylindrical containers and water flow have been established and dependencies have been obtained for determining coefficients of water resistance to their longitudinal and transverse displacement, depending on dimensions and velocity pattern. Dependences have been obtained for considering shallow water influence with longitudinal and transverse hose tanks under conditions of unlimited fluid and shallow water. Research application field. The research results can be used in developing methodology for calculating soft water-filled waterworks parameters for constructing fire ponds, protective dams and accumulating water reserves. The dependencies obtained for calculating water resistance to cylindrical hose-type tanks displacement in conditions of unlimited fluid and shallow water can be used when performing traction calculations and substantiating towing parameters during moving operations and deploying protective booms. Conclusions. Some issues of applying inflatable hose structures for constructing dikes and protective barriers have been studied. Research will be continued in the direction of parameters optimization, improving this type of structure construction and developing technologies for their installation.

Математична модель для визначення проєктних параметрів космічної надувної платформи з корисним навантаженням

The development and application of inflatable space structures is of considerable interest in modern space science and technology. Today, these structures enjoy wide application from aerodynamic inflatable deorbit means to inflatable residential sections for the International Space Station. This is because the masses of inflatable structures are smaller in comparison with others, which in turn minimizes the cost of their orbital injection. In view of the considerable interest in orbital constellations, the authors of this article propose the use of an inflatable space aerodynamic system as a platform for a payload. In doing so, we obtain a distributed satellite system on an inflatable space platform. The advantage of this technology is that it assures the maintenance of the relative position of the elements (payload) of a distributed satellite system of this type with minimal energy consumption. In its turn, to analyze the features of the operation of a particular space technology, its mathematical model is required. Because if this, the aim of the article is to develop a mathematical model for estimating the design parameters of an inflatable payload-bearing space platform. The mathematical model of the operation of an inflatable payload-bearing space platform developed in this work consists of three modules: a module of orbital motion, a module of calculation of the thermodynamic parameters of the inflatable platform, and a module of calculation of its variable inertia tensor. The article also identifies four gas modes of operation of the inflatable segment of the space platform and gives the inertia tensor as a function of the ambient temperature, which is necessary for further research. It should be noted that the application of the mathematical model allows a priori analysis of a wide range of inflatable space platform design parameters. On this basis, a design parameter analysis method that uses this model was developed. The application of this method may greatly simplify further research into the synthesis of an angular motion controller for an inflatable payload-bearing space platform, the choice of the design parameters of inflatable segment shell materials, and the study of the platform operation in different gas modes.

Form finding analysis of air cushion of underwater shaking tables

An air cushion, in the context of this study, is an inflatable membrane structure made of rubber-coated woven fabric reinforced composites. Inflatable membrane structures have wide application prospects in the waterproofing of underwater moving machineries, such as underwater shaking tables. A refining form finding analysis of a waterproof air cushion was carried out, and the mechanical characteristics in the process of form finding were studied. The air cushion had two layers. The lower layer is acted upon by air pressure, and the upper layer is acted upon by air and water pressure, both of which were theoretically analyzed. The dynamic equilibrium process of the air cushion was simulated by combining the Coupled Eulerian-Lagrangian(CEL) method with the fluid cavity analysis technology. The accuracy of the simulated results was verified by the theoretical analysis results. The dynamic equilibrium process of the air cushion with different initial inflation pressures was analyzed. The results show that the air cushion is most favorable when the initial inflatable pressure is slightly higher than the theoretical analysis result. Higher air pressure leads to higher stress of the air cushion, while lower air pressure will lead to slow stability during form finding. These results will provide a basis for engineering applications of air cushions in underwater shaking tables and in other fields.

Investigating the Growth of Algae Under Low Atmospheric Pressures for Potential Food and Oxygen Production on Mars

With long-term missions to Mars and beyond that would not allow resupply, a self-sustaining Bioregenerative Life Support System (BLSS) is essential. Algae are promising candidates for BLSS due to their completely edible biomass, fast growth rates and ease of handling. Extremophilic algae such as snow algae and halophilic algae may also be especially suited for a BLSS because of their ability to grow under extreme conditions. However, as indicated from over 50 prior space studies examining algal growth, little is known about the growth of algae at close to Mars-relevant pressures. Here, we explored the potential for five algae species to produce oxygen and food under low-pressure conditions relevant to Mars. These included Chloromonas brevispina, Kremastochrysopsis austriaca, Dunaliella salina, Chlorella vulgaris, and Spirulina plantensis. The cultures were grown in duplicate in a low-pressure growth chamber at 670 ± 20 mbar, 330 ± 20 mbar, 160 ± 20 mbar, and 80 ± 2.5 mbar pressures under continuous light exposure (62–70 μmol m–2 s–1). The atmosphere was evacuated and purged with CO2 after sampling each week. Growth experiments showed that D. salina, C. brevispina, and C. vulgaris were the best candidates to be used for BLSS at low pressure. The highest carrying capacities for each species under low pressure conditions were achieved by D. salina at 160 mbar (30.0 ± 4.6 × 105 cells/ml), followed by C. brevispina at 330 mbar (19.8 ± 0.9 × 105 cells/ml) and C. vulgaris at 160 mbar (13.0 ± 1.5 × 105 cells/ml). C. brevispina, D. salina, and C. vulgaris all also displayed substantial growth at the lowest tested pressure of 80 mbar reaching concentrations of 43.4 ± 2.5 × 104, 15.8 ± 1.3 × 104, and 57.1 ± 4.5 × 104 cells per ml, respectively. These results indicate that these species are promising candidates for the development of a Mars-based BLSS using low pressure (∼200–300 mbar) greenhouses and inflatable structures that have already been conceptualized and designed.

Reliability and effectiveness of laser scanners in future construction efforts on the Moon and Mars

The exploration and conquest of the Moon and Mars is very likely in the near future. Therefore the erection of lunar and Martian structures, suitable for permanent human presence is increasingly discussed by the scientific community. Various concepts have been proposed for creation of lunar and Martian permanent bases. Techniques ranging from 3D printing of concrete, through utilization of natural caves to inflatable pressurized tensile structures are considered. In authors' opinion a fast, accurate and remote measuring technique will be necessary for successful completion of majority of extra-terrestrial construction tasks. The terrestrial laser scanning technique should be used for the lunar and Martian construction projects. To assess the suitability of terrestrial laser scanning techniques which are going to be used on the Moon and Mars, initial measurements should be conducted on Earth. Unfortunately extra-terrestrial soils are not available for general research. The only feasible solution is to use lunar and Martian soil simulants to practice construction technologies, techniques and strategies. The main aim of this research programme is radiometric and geometric analysis of TLS point clouds collected during the measurement of lunar and Martian soil simulants targets. The conducted research programme was focused on the analysis of a laser beam dispersion and absorption in soil simulants. It should be noted that the dispersion and absorption of a laser beam for the scanned surface is a key factor in TLS remote measurements. The advantages and limitations of TLS technique for possible lunar and Martian applications was discussed. Areas of subsequent research were pointed out. In the first section the brief state-of-the-art was given in context of the conducted research programme. Subsequently, in section two used specimens and equipment was described. The third section of the paper was dedicated to present the conducted research programme. The achieved results were shown in section four in the form of tables and graphs. Finally, in section five the discussion was carried out and followed by a list of drawn conclusions. It was proved that TLS technique can be used to effectively scan LSS and MSS, thus scanning on the Moon and Mars is enabled.

Experimental and numerical research on the structural behaviour of a Tensairity dome

This paper introduces a novel Tensairity dome that combines the strengths of flexible members and rigid members. The structural performance for inflation, symmetric loading, and asymmetric loading is studied experimentally and numerically to show the application potential of the proposed structure. In the experiment, deformations were measured in a series of positions along the radial struts. The internal forces in the struts and cables were obtained using strain gauges during inflation and external loading. The load–displacement curves, variations of internal forces, and failure modes for the hybrid structure are discussed. The results indicate that the air pressure plays a critical role in introducing pre-stress to the structural system to obtain the ability to withstand external loads. Subsequently, a refined finite-element model was developed for nonlinear analysis and validated using the test results, demonstrating the effectiveness of the simulation method for the hybrid inflatable structures. This study reveals the structural principle of the proposed system and demonstrates its feasibility in construction engineering.

A Pneumatically Driven, Disposable, Soft Robotic Gripper Equipped With Multi-Stage, Retractable, Telescopic Fingers

Robots use their end-effectors to grasp and manipulate objects in unstructured and dynamic environments. Robot hands and grippers can vary from rigid and complex designs to soft, inflatable, and lightweight structures. In this paper, we focus on the modeling and development of a pneumatically driven soft robotic gripper with retractable telescopic fingers and finger bases with abduction / adduction capabilities. Both the main fingers and the base actuators use a pre-folded, telescopic structure facilitating passive retraction. The efficiency of the proposed device is experimentally validated through different types of experiments: i) grasping experiments that involve different everyday objects ranging from household objects and fragile items to medical waste and consumables, ii) force exertion experiments that capture the maximum forces that can be exerted by the proposed device when utilizing the different actuators of the gripper, and iii) grasp resistance experiments that focus on the effect of the inflatable structure on resisting environmental uncertainties and disturbances. The proposed gripper is able to grasp a plethora of objects, and can exert more than 14 N of grasping force. The design is so low-cost and modular that the soft fingers and palm pad of the gripper can be used in a disposable manner, facilitating the execution of specialized tasks (e.g., grasping in contaminated environments, handling of medical waste, etc). When it is not inflated, the gripper profile is thin and compact to facilitate storage.

Uniaxial tensile mechanical tests of Kapton foil at high-low temperature conditions

PurposeThis study aims to investigate the basic mechanical properties of inflatable antenna reflector material under high-low temperatures.Design/methodology/approachUniaxial tensile tests of Kapton (polyimide) foils were conducted in this paper. Kapton foils with a thickness of 25 µm were used and the strip specimens were manufactured according to the machine direction and the transverse direction of the foils.FindingsThe stress–strain curves of the foils were obtained under ten temperature conditions (−70°C, −40°C, −10°C, 0°C, 20°C, 50°C, 80°C, 110°C, 140°C, 170°C) after uniaxial tensile tests. Generally speaking, such stress–strain curves are highly nonlinear, and Kapton can be classified into some kind of ductile material without obvious yielding point.Practical implicationsThe tests results provide a basis for partial coefficients of Kapton foils strength design value, and meanwhile provide basic material data for the extreme temperature field test in orbit for the inflatable antenna structure in the future.Originality/valueBased on the curve itself and strain energy theory, for the first time the equivalent yielding point was determined and the mechanism of constitutive curve changing with temperature was explained. Based on curves above, tensile strength, elongation at break, equivalent yielding stress, yielding strain and elastic modulus were analyzed and calculated. By analyzing the mechanical parameters above, the fitting formulas with temperature as the variable were given.

Gripping, Catching, and Conveying With a Soft, Toroidal Hydrostat

This work demonstrates that a soft, toroidal hydrostat can be used to perform three functions found in both living and engineered systems: gripping, catching, and conveying. We first demonstrate a gripping mechanism that uses linear motion to drive the inversion of the toroid around objects, encapsulating them within a crumpled elastic membrane under hydrostatic pressure. This mechanism results in gripping forces ranging from 1–80 N, which depend predictably upon the geometric and material properties of the gripper and the object. We next demonstrate a catching mechanism akin to that of a chameleon’s tongue: the elasticity of the membrane is used to store mechanical energy and drive a rapid acceleration and inversion process (≈400 m/s2) to capture flying objects (e.g., a bouncing ball). Finally, we show how the soft topological structure can be implemented in a soft conveying mechanism which continuously inverts and passes objects through its center (~1 cm/s), serving a function like that of esophageal peristalsis (i.e., transporting objects through a tube), while eliminating the requirement of a lubricated interface and the coordinated actuation of a pressure wave. The hybrid hard-soft mechanisms presented here can be applied in the integration of soft functionality into conventional robotic systems for applications including the automation of agricultural and biological research processes. More generally, we show how inflatable structures comprising soft polymeric films arranged in complex topologies provide a promising approach to designing soft robotic systems with novel, bio-inspired functionality.

Computational inverse design of surface-based inflatables

We present a computational inverse design method for a new class of surface-based inflatable structure. Our deployable structures are fabricated by fusing together two layers of inextensible sheet material along carefully selected curves. The fusing curves form a network of tubular channels that can be inflated with air or other fluids. When fully inflated, the initially flat surface assumes a programmed double-curved shape and becomes stiff and load-bearing. We present a method that solves for the layout of air channels that, when inflated, best approximate a given input design. For this purpose, we integrate a forward simulation method for inflation with a gradient-based optimization algorithm that continuously adapts the geometry of the air channels to improve the design objectives. To initialize this non-linear optimization, we propose a novel surface flattening algorithm. When a channel is inflated, it approximately maintains its length, but contracts transversally to its main direction. Our algorithm approximates this deformation behavior by computing a mapping from the 3D design surface to the plane that allows for anisotropic metric scaling within the bounds realizable by the physical system. We show a wide variety of inflatable designs and fabricate several prototypes to validate our approach and highlight potential applications.

TwInflation

The general structure of Hybrid Inflation remains a very well-motivated mechanism for lower-scale cosmic inflation in the face of improving constraints on the tensor-to-scalar ratio. However, as originally modeled, the “waterfall” field in this mechanism gives rise to a hierarchy problem (η−problem) for the inflaton after demanding standard effective field theory (EFT) control. We modify the hybrid mechanism and incorporate a discrete “twin” symmetry, thereby yielding a viable, natural and EFT-controlled model of non-supersymmetric low-scale inflation, “Twinflation”. Analogously to Twin Higgs models, the discrete exchange-symmetry with a “twin” sector reduces quadratic sensitivity in the inflationary potential to ultra-violet physics, at the root of the hierarchy problem. The observed phase of inflation takes place on a hilltop-like potential but without fine-tuning of the initial inflaton position in field-space. We also show that all parameters of the model can take natural values, below any associated EFT-cutoff mass scales and field values, thus ensuring straightforward theoretical control. We discuss the basic phenomenological considerations and constraints, as well as possible future directions.

Multi-objective characterization of an inflatable space structure with a quasi-static experimental deflation and finite element analysis

We propose a methodology for the multi-objective characterization of a light, single layer orthotropic fabric inflatable space structure. The presented approach focuses on a custom in-situ experimental quasi-static deflation, semi-empirical development of flow coefficients and structural integrity loss parameters as well as process validation with finite element analysis. The experiments are designed to investigate a collapse of a thin, deployable, one segmented inflatable structure caused by a simulated single leak and passive porous leakage through the fabric material. The acquisition of real time data with a custom designed standalone ambient conditions sensing platform and the wireless internal sensing unit furnishes pressures, temperatures, mass flow rates, dynamic strains and accelerations. Synchronously, geometric changes in the shape of the structure's representative area are recorded utilizing photogrammetry. The non-wireless and wireless outputs are treated with a series of smoothing, best-fitting and refining operations and combined with the corresponding sequence of active surface area photogrammetric results. The formulation of inflatable characterization parameters and a single leak/passive porous leakage structural integrity loss ratios allows for an in depth description of the inflatable structure behavior. A closer examination of the experimental data shows that the majority of the structural integrity loss ~97% is attributed to the sudden and relatively short leak due to puncture and the remaining ~3% to the slow and prolonged pressure loss caused by the passive porous areal leakage through the membrane. A semi-empirical framework based on a thermodynamic equilibrium produces sets of single leak, passive porous leakage and active area coefficients to be validated with the Ls-DYNA® finite element simulation of a polyurethane coated nylon fabric inflatable structure model. We use implicit and explicit fea of a control volume deflation to validate the aforementioned coefficient curves and constants. The subsequent comparison with the experimental internal temperature, internal pressure and mass flow rates results in a 1.83%, 0.61% and 1.19% difference respectively for the single leak events. The successive contrasting with the experimental internal temperature, internal pressure and active area produces 2.04%, 1.26% and 1.68% difference for the passive porous leakage respectively. We demonstrated that the multi-objective, structural integrity loss characterization techniques for the space structures have promising capabilities for the application in inflatable structures of diverse shapes and sizes.

Reliability-based design assessment of offshore inflatable barrier structures made of fibre-reinforced composites

Analysis and design of inflatable structures made of fibre reinforced composites have been the focus of many researchers in recent times. As with most designs, sources of uncertainty, variability and bias in the performance of the designed structures exist and should normally be assessed. This paper thus, seeks to identify and quantify levels of uncertainties that are in the design of a typical inflatable fender barrier structure against impact loadings and conducts reliability-based evaluation toward understanding safety levels and factors of safety to be employed for its design and for similar structures. Using a previously validated 3D parametric fluid-structure interaction analysis results of the model, implicit limit state response surface-based performance functions were derived for the structural responses to loads for the complex stresses and strain modes of failures. The First Order Reliability Method (FORM) was used to evaluate the influence of the uncertainties in materials and load parameters and hence the safety margins for the modes of failures considered. The findings in this study will provide benchmark levels for practicing engineers in carrying out optimal design of similar inflatable structures with acceptable safety levels.