Basic morphometric parameters of the biostatic donkey body model

The domestic donkey (Equus asinus) has a very specific body construction. It is built in such a way that the mutual relationship of individual body regions enables great work endurance. The fact that this breed of domestic animal originates from wild ancestors, originated and developed in Africa, clearly shows that the breed developed in harsh climatic and ecological conditions that conditioned the appropriate biological response. The biostatic model causes the biodynamic effect, i.e., the production of biokinetic energy. Movement forwards occurs as a consequence of the creation of biokinetic energy and its transfer from the back part of the body, where it originates, to the front part of the body. The most efficient transfer of biokinetic energy is enabled by the existence of an appropriate biostatic model, i.e., body structure, and this leads to a biodynamic effect that is defined as a movement. For the process of movement, the muscles must be well developed. Two muscle groups are distinguished; a) pelvic muscles, b) external hip and croup joint muscles. The basic lever for the transfer of biokinetic energy is the femur. The generated energy is transferred from the hip joint to the thigh muscles, which shortening leads to the movement of the hind leg forward, its leaning against the ground and pushing the whole body forward. The generated biokinetic energy cause the bio kinematic effect, which is characterized as a movement.

Theory and Application of Gob-Side Entry Retaining in Thick Three-Soft Coal Seam

With the characteristic of less roadway excavation and high resource recovery, gob-side entry retaining (GER) technology is a safe and efficient green mining technology. Many experts and scholars have done extensive research on its principle and application. However, GERs are rarely used in thick soft coal seams. In this paper, based on the geological conditions of a coal mine in China, we propose a novelty approach of GER in thick three-soft coal seam (it means a single seam with a soft roof and a soft floor). The engineering scheme includes roadway expansion, large section roadway support, cutting roof to relieve pressure, and road-inside backfill body construction. The established mechanical and numerical calculation models effectively guide the engineering practice. Field observations showed that all the processes met the requirements of field production. The research results could provide theoretical guidance for the application of GER under similar geological conditions.

INFLUENCE OF CREEP CONCRETE ON SPACE STABILITY THIN-WALLED DOME COVERINGS

The task was set, due to the capabilities of modern software systems, to assess the effect of the increase in inelastic deformations under prolonged load action on the loss of stability of thin-walled dome coverings. The study of the dependences of the forms of the loss of stability of dome covering from creep concrete that will help further with optimization calculations when determining of the most influencing parameters of designs. Calculation results of thin-walled concrete dome roof of circular outline under the influence of operational loadings with use of two modern program complexes are given in article. It is investigated intense and deformation condition of dome coverings as a part of construction from position of forecasting of possible forms of loss of stability, with use of opportunities of the final and element «MidasCivil» computer system. In work provisions of the theory of elasticity, mechanics of deformation of solid body, construction mechanics and also methods of mathematical modeling based on application of finite element method are used. The received results give the chance to rationally select geometrical parameters and material of design and also to set structural strength safety factors at the solution of problems of stability of different covers taking into account possible creep of material.

RANCANG BANGUN KONSTRUKSI BODI PADA AUTOMATIC WELDING CARRIER MACHINE

Manually system welding process still widely used and have a deficiency in it. Which work is accident often occur in it, the unstable arc of fire and quality of welding product still depends on the welder ability. The purpose of this study is to design a portable robotic welding tool equipped MIG(Metal Inert Gas) welding tool to support automation in the welding process. Mobility and work range of tools is supported by light and strong material and designed with relatively small dimensions and equipped leg robotics which is useful to adding work range of the tool in every single welding process. This study using experimentally and simulations methods in body construction and empirical calculation to know relevantly the result and simulation process. And the data obtained after calculating with imposition 98 N, pressure stress on the body is 3334 Pa, which is smaller than the Modulus of Elasticity Aluminum alloy type 5052, moreover, materials used are capable and safe. The riveted joint of the extensions of the body has fracture resistance 2,8 kN and used efficiency of 70% moreover this kind of extensions are efficient to apply on Automatic Welding Carrier Machine’s body.

Friction Characterisation for a Tumbling Self-Piercing Riveting Process

Due to increasing demands regarding ecological and economic specifications in vehicle design, the effort required for production is continuously increasing. One trend is the increased use of multi-material systems, which are characterised by the use of different materials such as high-strength steels or aluminium alloys. In addition to the varying mechanical properties of the components, an increased number of variants accompanied by different geometries is leading to increasing challenges on body construction. For the assembly and connection of the individual components, conventional joining methods reach their limitations. Therefore, new joining methods are necessary, which feature properties of versatility and can adapt to process and disturbance variables. One way of achieving tailored joints is to use a tumbling self-piercing riveting process. For the design of the process route, numerical investigations are necessary for which a characterisation of the friction properties is necessary. This paper therefore investigates the contact and friction conditions that occur in a tumbling self-piercing riveting process. The individual contacts between the process components are identified and based on this, suitable processes for the characterisation of the friction factors - and coefficients are selected and performed.

Some Formability Aspects of High Strength Steel and of Consisting Tailor Welded Blanks

In recent years, the demand for a reduction in pollutant emission has become extremely important in the vehicle industry. It can be achieved through fuel consumption reduction, which is a direct function of the vehicle’s weight. nowadays weight is widely controlled by the use of advanced- and ultra-high strength steels (AHSS and UHSS) in vehicle body construction. With the application of such steel sheets as chassis elements, crashworthiness can be maintained next to reduced sheet thicknesses, too. In this paper, the deep-drawability and springback after V-die bending is monitored for three types of AHSS grades, namely DP600, DP800 and DP1000 materials. The investigations are extended to tailor welded blanks (TWBs), made by the aforementioned steels coupled with a cold rolled steel sheet (DC04). Our results show that deep-drawability reduces with both the increase in strength and the increase in strength difference between the components in the TWBs. Furthermore, the higher strength is shown to cause higher spring-back. The TWBs have unique spring-back behavior around the weld line.

DEVELOPMENT OF INTERACTIVE MULTIMEDIA USING LECTORA INSPIRE FOR VEHICLE BODY CONSTRUCTION COURSES IN UNIVERSITAS SRIWIJAYA

This study aims to developing interactive multimedia using Lectora inspire for vehicle body construction courses for Universitas Sriwijaya students. The Lectora inspire software was used because easy to operate and can be made interactive electronic learning. Research and development method were used because it is an effective for developing multimedia and able to test the effectiveness of the product. Based on results, the interactive multimedia using Lectora inspire software are valid with percentage of 87.5% for multimedia and 86.9% for matters, practice with percentage in small group test of 85.52% and field test of 86.61%, and effective because based on post-test results 80% of respondents was passed. Thus, interactive multimedia using Lectora inspire software for vehicle body construction courses proper to use in Mechanical Engineering Education study program, Universitas Sriwijaya.