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Soft rod-climbing robots have been known to have great potential in a wide variety of working conditions, including cable inspection and pipeline maintenance. However, one of the most notable issues preventing their popular adoption is their inability to effectively cross obstacles or transfer between rods. To overcome these difficulties, this paper aims to propose an inchworm-inspired soft robot with omni-directional steering.

Theoretical models are first established to analyze the telescopic deformation, bending, steering and climbing ability of the soft robot. The main modes of movement the soft robot is expected to encounter is then determined through controlled testing so to verify their effectiveness (those being rod climbing, steering and obstacle surmounting).

The soft robot demonstrated a capability to cross obstacles 1.3 times its own width and bend 120° omni-directionally, evidencing outstanding abilities in both omni-directional steering and obstacle surmounting. In addition, the soft robot also exhibited acceptable climbing performance in a variety of working conditions such as climbing along vertical rods, transferring between rods with differing diameters or friction surfaces and bearing a payload.

The soft robot proposed in this paper possesses abilities that are both exceptional and crucial for practical use, specifically with regard to its omni-directional steering and obstacle surmounting.

The purpose of this paper is to derive the exact analytical expressions for torsion and bending creep of rods with the Norton-Bailey, Garofalo and Naumenko-Altenbach-Gorash constitutive models. These simple constitutive models, for example, the time- and strain-hardening constitutive equations, were based on adaptations for time-varying stress of equally simple models for the secondary creep stage from constant load/stress uniaxial tests where minimum creep rate is constant. The analytical solution is studied for Norton-Bailey and Garofalo laws in uniaxial states of stress.

The creep component of strain rate is defined by material-specific creep law. In this paper the authors adopt, following the common procedure Betten, an isotropic stress function. The paper derives the expressions for strain rate for uniaxial and shear stress states for the definite representations of stress function. First, in this paper the authors investigate the creep for the total deformation that remains constant in time.

The exact analytical expressions giving the torque and bending moment as a function of the time were derived.

The material isotropy and homogeneity preimposed. The secondary creep phase is considered.

The results of creep simulation are applied to practically important problem of engineering, namely for simulation of creep and relaxation of helical and disk springs.

The new, closed form solutions with commonly accepted creep models allow a deeper understanding of such a constitutive model's effect on stress and deformation and the implications for high temperature design. The application of the original solutions allows accurate analytic description of creep and relaxation of practically important problems in mechanical engineering. Following the procedure the paper establishes closed form solutions for creep and relaxation in helical, leaf and disk springs.

Three‐dimensional photonic bandgap (PBG) structures using alumina (Al₂O₃) as the high permittivity material were modeled and then the structures were fabricated by Fused Deposition of Multi‐materials (FDMM) technology. A finite element method and a real‐time electromagnetic wave propagation software were used to simulate and design the layered PBG structures for applications in the microwave frequency range. The modeling predicted a 3‐D photonic bandgap in the 16.5–23.5 GHz range. FDMM provides a computer‐controlled process to generate 3‐D structures, allowing high fabrication flexibility and efficiency. Electromagnetic measurements displayed the presence of a bandgap between 17.1–23.3 GHz, showing a good agreement with the predicted values. These PBG structures are potential candidates for applications in advanced communication systems.

Presents numerical algorithms which easily solve both optimal distributed and optimal boundary control problems in a space‐time domain. Analyses two simple cases of continuous systems. These are the vibrating string and the axially vibrating rod. Using finite difference recurrence schemes, gives numerical results which compare the behaviour of the controlled and uncontrolled systems. Compares the results for special cases in which analytical solutions are obtainable are compared with the results using the general numerical schemes.

The paper aims to present the original and easy for application methods of mechanical strength and electrical properties examination of conductive adhesives and adhesive joints at room as well as at liquid nitrogen temperatures.

The Epoxy Technology EPO‐TEK E4110 and EPO‐TEK H20E adhesives were investigated both in the form of the loose rod and as the printed layers on alumina substrates. Additionally, the mechanical and electrical properties of adhesive joints in low temperatures were investigated, where their characteristics depended on the physical properties of joined elements.

The results indicate the substantial influence of the substrate material on the adhesive resistivity. The joints samples were exposed to multiple thermal shocks in the range from room down to liquid nitrogen temperatures and it was observed that the joints strength and resistance stability could be reached in determined curing conditions of the adhesive.

It is generally stated that tested adhesives can be fully suitable for work in low temperatures. However, it should be underlined that these adhesives' properties change after cooling them down to the liquid nitrogen temperature – the strength growths and the resistance diminishes (about few times).

The paper examines mechanical strength and electrical properties of conductive adhesives and adhesive joints at various temperatures.

The authors search the optimal distribution of bending flexure along the axis of the rod. For the solution of the actual problem, the stability equations take into account all possible convex, simply connected shapes of the cross-section. The authors study the cross-sections with equal principal moments of inertia. The cross-sections are similar geometric figures related by a homothetic transformation with respect to a homothetic center on the axis of the rod and vary along its axis. The cross-section that delivers the maximum or the minimum for the critical eigenvalue must be determined among all convex, simply connected domains. The optimal form of the cross-section is known to be an equilateral triangle. The distribution of material along the length of a twisted and compressed rod is optimized so that the rod must support the maximal moment without spatial buckling, presuming its volume remains constant among all admissible rods. The static Euler's approach is applicable for simply supported rod (hinged), twisted by the conservative moment and axial compressing force.

The optimization problems for stability of twisted and compressed rods are studied in this manuscript. The complement for Euler's buckling problem is Greenhill's problem, which studies the forming of a loop in an elastic bar under simultaneous torsion and compression (Greenhill, 1883).

For determining the optimal solution, the authors directly compare the twisted rods with the different lengths and cross-sections using the invariant factors. The solution of optimization problem for simultaneously twisted and compressed rod is stated in closed form.

(1) The linear stability equations are applied. (2) No nonlinear or postbuckling effects were accounted. (3) The moment-free, ideal boundary conditions on both ends of the rod assumed.

One of the most common design cases in mechanical engineering is the concurrent compression and twisting of the straight members. The closed-form solution allows the immediate estimation of the optimization effect for axes and rotors in industrial and automotive engineering.

The application of lighter and material-saving structural elements allow the saving fabrication resources, reducing the mass of vehicles and industry machines. The systematic usage of material optimized structural elements assists the stabilization of global energy balance of Earth.

Albeit the governing ordinary differential equations are linear, the application of the optimality conditions leads to the nonlinearity of the final optimization equations. The search of closed form solution of the nonlinear differential equations is one of the mathematically hardest tasks in engineering mathematics. The closed-form solution presents in terms of higher transcendental functions.

For the climbing rod object with large diameter variation and the need of obstacle crossing, this paper aims to propose a new embracing-type climbing robot named as EVOC-I robot.

The design philosophy and structural scheme are introduced. The kinematic analysis of embracing and telescoping mechanisms is carried out to provide the theoretical foundation for the effective climbing of the robot. Based on the prototype robot, three preliminary experiments are carried out to verify the effectiveness of the designed robot.

The theoretical and experimental analyses have verified the reasonability and effectiveness of the proposed robot design.

As the preliminary study, the prototype still need a lot of improvement. The experimental verification is also limited. Future work will focus on improving the design and increasing the theoretical analysis, especially increasing experimental study and designing the next generation of the rod climbing robot.

The designed climbing robot can be used for climbing the rod with variation diameter and flange obstacle, especially the lightening rod in the transformer substation.

The paper designs a new climbing robot that integrates the ability of large variation diameter adaptation and obstacle crossing.

The purpose of this paper is to investigate the performance of intumescent coating on tension rod systems and their components. Steel tension rod systems consist of tension rods, fork end connectors and associated intersection or gusset plates. In case of fire, beside the tension rods themselves, the connection parts require appropriate fire protection. Intumescent fire protection coatings prevent a rapid heating of the steel and help secure the structural load-carrying capacity. Because the connection components of tension rod systems feature surface curvature and a complex geometry, high demand is placed on the intumescence and thermal protection performance of the coatings.

In this paper, experimental studies were carried out for steel tension rod systems with intumescent coating. The examined aspects include the foaming and cracking behaviour, the influence of different dry film thicknesses, the heating rate of the steel connecting parts in comparison to the tension rods, and the mounting orientation of the tension rods together with their fork end connectors.

The results show that a decrease in surface curvature and/or an increase in mass concentration of the steel components leads to a lower heating rate of the steel. Moreover, the performance of the intumescent coating on tension rod systems is influenced by the mounting orientation of the steel components.

The findings based on fire tests contribute to a better understanding of the intumescent coating performance on connection components of tension rod systems. This subject has not been extensively studied yet.

A numerical procedure is devised for the thermal analysis of three‐dimensional large truss‐type space structures exposed to solar radiation. Truss members made of an orthotropic material with a closed thin‐walled cross‐section of arbitrary shape are considered. Three‐dimensional thermal effects are taken into account in the analysis. In the proposed method, the governing equations are first put into a weak form. Then the Galerkin finite element method is applied with respect to the axial coordinate of each truss member. The circumferential variation of the temperature is treated by a symbolically‐coded harmonic balance procedure. The interaction between the various truss members is controlled by an iterative scheme. As a numerical example which demonstrates the proposed method, the temperature distribution in a parabolic dish structure is found. The results are compared to those obtained by standard one‐ and two‐dimensional analyses.

The current industry standard rigid spinal implants suffer fatigue failures due to bending and torsion loads. The purpose of this program was to design novel prototype flexible titanium alloy spinal implant rod with machined features, and then apply the laser shock peening (LSP) process to restore the fatigue strength debit due to these features.

A flexible prototype rod was designed with flat section at the center of the rod. The flat section was laser shock peened. Static compression tests were conducted as per American Society of Testing Materials standards for three‐ and four‐point bending tests and “vertebrectomy” constructs. Finite element models were developed to aid in the design of LSP and also to guide the experiments.

The test results indicated a ∼3X improvement in flexibility and a reduction in fatigue load ratio, defined as applied load divided by the yield load; from 72 to 68 percent. This rod was LSP's on the flat sections, and tested again. The results indicated an increase in the fatigue load ratio from 68 to 75 percent without any further change in flexibility.

It has been demonstrated successfully that the current industry rigid spinal implant rod can be modified for flexibility and laser shock peened to increase fatigue strength. This enhancement will enable the use of the implant for longer periods and higher loads; and for surgical processes with and without fusion. This technology can be readily applied to all metals that are certified for human implant applications; thus can be implemented with minimal clinical trials.