Applied Mechanics and Materials Vol. 461

Abstract: Barnacle is a unique sessile crustacean, which produces a multi-protein complex historically called barnacle cement to attach to diverse immersed materials permanently. The proteinaceous cement exhibits powerful adhesive property and special waterproof capability to cure at solid-liquid boundaries, which makes it ideal biomaterial for technical, medical and dental applications. It has been proved that a 19 kDa protein component, termed cp-19k in the cement plays a key role in surface coupling during underwater attachment. To verify whether the bacterial recombinant 19 kDa protein retains the adhesive ability, we cloned and sequenced the Bacp-19k gene in Balanus albicostatus. It encodes 173 amino acid residues, with seven biased ones, Thr, Lys, Gly, Ala, Val, Ser and Leu, comprising about 80% of the total. Two amino acid substitutions (F69L, I106L) were discovered in Bacp-19k due to the polymorphisms in barnacle cp-19ks, compared with the submitted one (GenBank: AB242295.1). Recombinant Bacp-19k was highly expressed in host strain Escherichia coli BL21 (DE3) and purified by affinity chromatography. Adsorption of recombinant Bacp-19k to glass substrata was examined by Coomassie brilliant blue staining. Future study will reveal the relationship between specific structures and functions for molecular design of novel biomimetic underwater adhesives.

Abstract: Computational fluid dynamics (CFD) technique is considered as an effective approach for analysis of fishlike swimming, which quantitatively visualizes interaction between fishes and their fluid environment. This paper proposed and developed a simulation environment for understanding fish locomotion and hydrodynamic effects during the self-propulsion in a flow field. Approximate kinetic model or/and shape description based camera observation are recommended to specify active deformation of the body. Burst-Coast swimming is analyzed as an illustration of the simulation platform.

Abstract: The similarity phenomenon exists widely in nature and similarity theory is of importance in various types of engineering problems, especially in bionic engineering. In this work,a conception of fuzzy similarity was introduced. An effective mathematical method was put forward to identify the extent of morphological similarity between two living things of the homogenous species or the heterogeneous species and quantitative analysis of the similarity degree was carried out. A computer program based on the genetic algorithm was developed to solve and optimize the numerical scaling coefficient between an original profile data and a target one. To seek the maximum fuzzy similarity degree, an object function which is the core idea in this method was built to compute the similarity coefficient according to the corresponding points in these two sample profiles. Moreover, a series of arrays from the profiles of the foreleg of praying mantis (Mantis religiosa Linnaeus) was imported into the program. The results indicated the fuzzy similarity degree of samples was considerably high, which means the shape of the praying mantiss apical claw is quite uniform. Therefore, this computation method of similarity degree is effective.

Abstract: The ancient wall paintings and earthen architecture ruins are the most important part of cultural heritage. Inhabitation and locomotion of animals are major factors that lead to biodegradation and biodeterioration at the cultural heritage sites. In this miniview, based on our team work of cultural relics conservation in recent years, the latest findings domestic and overseas in fields of ethology and bionics were summarized, focusing on the correlated methods and techniques that can be used into cross-over study of cultural relics conservation. Animal's biting, nesting, cocooning, crawling, and scratching are all behavioral process that easily bring damage to cultural heritage, such as ancient murals, architectures, earth ruins and so on. Both modern video record techniques and animal motion trajectory analysis may be taken use to improve the analytic accuracy of gait information for animals that crawling on the surface of cultural relics, which promoted the related study of motor pattern, behavior process, and damage pattern of animals to cultural relics. The three dimensional tiny force sensor with high resolution can be used for measuring normal adhesive force and tangential friction force of animals that contacted the surface of fragile cultural relics, which make animal adhesion modeling and historical relics mechanical model constructing possible, and provide newly evidence for biomechanics process illumination of animals locomotion. Totally, the application of the bionic techniques to the study of animals behavioral characteristics will provide new opportunity to better clarify the biological damaging mechanisms of cultural relics and control animal bioderioration, which will drive the development of cultural relics conservation technology in the near future.

Abstract: During the application of solid expandable tubular (SET) technology, the friction between expansion cone and tubular results in high expansion pressure, high operational risk, and severe abrasion of expansion cone over long distance operation. So far, traditional methods have not been able to effectively achieve the purpose of reducing the friction and improving the wear resistance of expansion cone. The bionic non-smooth surface has been studied and confirmed to have characters of reducing friction and wear, and these characteristics have been successfully applied in many fields. In this paper, the bionic non-smooth theory was applied on the surface of expansion cone, and bionic cone was fabricated by laser texturing and carbon based coating. The ground tests proved that the bionic surface treatment on the expansion cone could reduce the expansion pressure by 15% at least and improve the wear resistance.

Abstract: A study was done on agricultural enterprises technology innovation based on the management bionics method. From the perspective of bionics, this study investigates influence factors, mechanisms and team building of agricultural enterprises technology innovation based on the scientific and normative analysis of management bionics. Through standardized management bionic analogy analysis, the following analogies were drawn: agricultural enterprises technology innovation influence factors and the onion biological form, agricultural enterprises technology innovation mechanism and the biological enzyme catalytic reaction mechanism, agricultural enterprises technology innovation team building with the bee biological group effect. Therefore, three bionic element models of agricultural enterprises technology innovation were built, namely agricultural enterprises technology innovation onion model, technology innovation enzyme catalytic reaction bionic model and the bees’ team effect bionic model. This study ends with the corresponding bionic strategies and suggestions about agricultural enterprises technology innovation, which may provide references for the development of agricultural enterprises technology innovation in China. At the same time, this study also enriches the research range and theoretical system of management bionics.

Abstract: Grasshopper [Chondracris rosea rosea (De Geer)] possesses sharp and serrated incisors that have an advantageous capacity for cutting plant. The special outline of the incisor lobe described by reverse engineering was used for the prototype of the teeth of bionic saw manufactured by Wire Electronic Discharge Machine. In total one traditional saw and four bionic saws (which teeth are full teeth, first teeth, second teeth, and third teeth) were manufactured and compared for the cutting property. The experiments for cutting corn stalk using bionic saws and traditional saw were conducted in laboratory conditions using universal testing machine at quasi-static speed of 4 mm per second. The results show that the cutting force and the average energy consumed for cutting corn stalk using bionic saw is lower compared with commercial saw. 8.95 J consumed for cutting a corn stalk using bionic saw of full teeth in average is lower by 12.85% than 10.27 J needed for traditional saw. In additional the average cutting force for four types of bionic saws is lower than that of traditional saw. The least average force is 41.11 N for bionic saw of first teeth much lower than 71.97 N for traditional saw. In conclusion, the special shaped incisors of grasshopper are a potential prototype that can be exploited to develop new cutting element to cut lignocellulosic biomass more efficiently. These results would be helpful for designing cutting elements on crop harvesting, biomass size reduction and other processing machinery.

Abstract: The rear under-run protection devices (RUPD) could prevent the entry of a small vehicle under rear side of the heavy truck, and decrease the injuries and deaths when the accident occurs. In this paper, a new concept of the mechanical design of heavy truck RUPD is presented based on the bio-inspired method, by analyzing the structure of a kind of sheep horn, which has good capacities of energy absorption and structural strength. Firstly, the space geometry characteristic of the sheep horn in macroscopic view was analyzed. Then the research was focused on its mechanical property, and the microstructure of the horn sample was observed by the scanning electron microscope (SEM). Based on the test results, the structure characteristic and force condition of the horn were discussed. A new RUPD structure was designed in both macro and micro levels using bionic principle. The superior mechanics performance of the sheep horn was transplanted into the new RUPD. Finally, the finite element model for the new RUPD, which is inspired from the sheep horn, was established and analyzed. Simulation results showed that the protection device had better strength characteristic and could effectively protect car occupants in under-run accidents. Therefore, with the remarkable strength performance and simple structure, the bionic RUPD shows the promise for practical application.

Abstract: Perching with Unmanned Aerial Vehicles (UAVs) has been an emerging topic in the field of biomimetic engineering during last decade. Taking the newly designed gripping mechanism into account, a control strategy for autonomous perching with a quadrotor is further proposed, implemented and validated in this paper. Based on the perching procedure of birds in nature, this article focuses on the steps of engaging with the target during perching, latching to the target after engagement and releasing from the target when de-perching. The autonomous control strategy is integrated into the gripping mechanism after it is derived. Experiments on its effectiveness and reliability with a quadrotor are finally conducted, showing that the control strategy is capable of autonomously perching a quadrotor to a target pole.

Abstract: In order to solve the torque control problem in electric power steering using induction motor,the system mathematical model was established and the impact on the torque control caused by the variation of rotor resistance was analyzed. Using feed-forward and feedback integrating control and on-line resistance identification to improve the accuracy of torque control and current tracking response. Simulation comparisons showed that the proposed method could significantly improve the current response speed and accuracy in induction motor control of electric power steering system.