Standardization of Jib Crane Design by F.E.M. Rules And Parametric Modeling

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1 Standardization of Jib Crane Design by F.E.M. Rules And Parametric Modeling Sandip D. Shinde 1 1 PG Student Department of Production Engineering, S.G.G.S.I.E.&T. Nanded , Maharashtra, India. sdshinde14@gmail.com Abstract Standardization of jib crane design procedures enables designers to develop their own jib crane automation modules for entire jib crane design applications. Since main effort and time for implementation of the jib crane design procedures are generally spent for interpretation and explanation of the available jib crane design standards, a computer-automated access by using parametric modeling to the available standards may improve speed, reliability and quality of the design procedures. Starting from the fact that components of jib cranes are generally composed of similar mechanical and electrical sub-components independent of the crane type, a general component tree of jib cranes is developed for automation purpose. Design Modules of cranes are defined from the developed component tree of the cranes based on the available design procedures. Independent Design Procedures are defined as atomic design modules of the jib crane design procedures by considering computational approaches and rules in the "F. E. M. Rules" for each jib crane component. The "F. E. M. rules" is selected for this purpose because of its widespread use and established popularity among the jib crane manufacturers. Access to the "F. E. M. Rules" from any design procedure is fully automated by using a systematic approach of parametric modeling. The parametric model can be used for various jib crane design cases as well as further for optimization. Ref. [6] Index Terms F.E.M. Rules, Jib Crane Design, Computer Automated Design, Parametric Modeling. I. INTRODUCTION Jib Cranes are industrial machines that are mainly used for materials movements in construction sites, production halls, assembly lines, storage areas, power stations and similar places. Their design features vary widely according to their major operational specifications such as: type of motion of the crane structure, weight and type of the load, location of the crane, geometric features, operating regimes and environmental conditions. However, an appraisal of the available literature reveals that procedural design of jib cranes are highly saturated and standardized in various industrial companies and organizations independent of the jib crane type. Consideration of the available technology that is mainly based on the accumulated previous experience is important for better performance, higher safety and more reliable designs. It is well known that generic features of jib crane components are similar for various different types of cranes. Since the jib crane design procedures are highly standardized with these components, main effort and time spent in jib crane design projects are mostly for interpretation and implementation of the available design 145 standards. Many national and/or international standards and rules offer design methods and empirical approaches and formulae that are based on previous design experiences and widely accepted design procedures. It is believed that computer automated access to these standards with pre-loaded interpretation; parametric modeling and guidance rules increase speed and reliability of the design procedures and increase efficiency of the jib crane designers. Ref. [1] II. CAD/CAM/CAE IN JIB CRANE DESIGN CAD/CAM/CAE is used mainly for two purposes in a jib crane design process. The first is procedural programming that enables designers to make lengthy and tedious calculations in a short time. This also includes use of CAD techniques and reduces the design time significantly. Another approach is the use of CAE for expert system applications. CAE are used mainly in selection and decision making stages of the design process. It is believed that Design Automation by using CAE may result in significant improvements on designers productivity. Greater consistency of design, ability to explore more alternatives and integration of the design/analysis/documentation processes are most significant advantages of the design automation by using parametric modeling. There are many design automation software packages and many more expert systems developed for industrial applications on various fields. If we use Ansys Parametric Design Language (APDL) in this field then it is really helpful for Design Automation and is aimed to obtain least cranage cost by calculating the combined use of different types of jib cranes Ref. [4]. The ANSYS Workbench platform is an environment that offers an efficient and intuitive user interface, reliable and tight CAD integration, automatic meshing, and access to model parameters. Basing current and future development on this architecture, ANSYS are able to provide a single, integrated simulation environment for its entire product range including structural, electromagnetic and CFD disciplines. Furthermore, through its multi-physics capabilities, coupled problems, such as fluid-structural interaction, can also be undertaken within this framework, using common mesh and geometry manipulation tools. A key component of Workbench is that it has been specifically developed to enable parameterization of the entire simulation model, including geometric, material and boundary condition variables. As ANSYS supports native, bi-directional, integration with the most popular

2 CAD systems, the designer can make direct reference to parameters defined when initially creating the solid model. Consequently, a simulation-driven product development strategy can be adopted by the user, where CAD modifications are automatically directed from the results of the simulation. Ref. [7] III. STRUCTURE OF THE "F. E. M. RULES" "FEM Rules" is mainly a collection of rules (not procedures) to guide the jib crane designers. Many requirements are implied within the "FEM Rules", but explicit and detailed statements towards established design calculations are not available. This is very convenient for jib crane designers of different companies and institutions, since each company has its own knowhow and experience to be implemented in their own jib crane design technology. Overwhelming features of the "FEM Rules" are stated below: Ref. [6] Extensive classification of jib cranes and crane components for the purpose of design, Classification and identification of jib crane Loads for safe and reliable crane design, Strength and stability requirements to be satisfied for various load (including test loads) conditions, Informative for non-critical jib crane components. A schematic representation of structure of the "FEM Rules" is given in Figure 1. The figure summarizes the outline of the text of the FEM Rules from a topical view. The "FEM Rules" starts with a classification of jib cranes and their mechanisms/components and continues with the discussion of loads and their identification and related stress/deflection analysis. It also includes criteria to decide on the external loads, to select crane components and to test the manufactured cranes. Ref. [3] 1. Classification of Jib Crane 2. Classification of Jib Crane Load for Safe & Reliable Design 3. Strength & Stability Requirements 4. Informative For Non- Critical Jib Crane Components. Figure 1. Structure of the "F. E. M. Rules" IV. COMPUTER AUTOMATED ACCESS TO THE "F. E. M. RULES" The first phase of this study is to computerize access to the "FEM Rules" through a jib crane design code. This is achieved by automated access to the elements of the "FEM Rules" in a Design Modeler environment [6]. This software packages are developed and integrated such that related recommendations, computational procedures and data are transferred mutually during the runtime. Following benefits are expected from the development of a computer-automated procedure for jib crane design: Development of an established design procedure, Elimination of any misinterpretation of the Standards for jib crane design during limited design period, Elimination of absolute dependence on human experts, hence inexperienced designers may be employed in a design project, Accumulation of previous experience in a systematic manner that will lead to an intelligent design database. Ref. [5] The program structures for jib crane design automation are developed, analyzed and tested in detail during this study. These are explained in the following sections. A. Modeling and Geometry Editing Tailored For Simulation Creating design models is a core part of product development and the first step in the simulation process. These models can be of a geometry form representing the actual design detail, or they can be an approximation of the design using simplified components like beams and plates. Simulation often demands unique modeling capabilities that typical CAD operations do not require. Therefore, these capabilities are either lacking in CAD systems or implemented in a fashion that is not optimum for performing simulation-related functions. Design Modeler is a Workbench application from ANSYS that provides modeling functions unique for simulation that includes detailed geometry creation, CAD geometry modification and concept model creation tools. Ref. [7] B. Detail Geometry Creation Design-Modeler offers geometry creation features like extrude, revolve, sweep, and chamfer functions and others to create fully parametric models. The models can be used with any core ANSYS simulation product or with add-on tools like ANSYS Design-Xplorer to perform design optimization. Ref. [7] C. Concept Model Creation Concept models are used in a product development process prior to creating any detailed CAD geometry. Design approximations-along with simulation results-are extremely useful in making fast product decisions early in the design cycle when product costs can be impacted significantly. Design-Modeler has tools for creating these models quickly and then, with ANSYS simulation tools, easily predicting how the proposed design will perform. Ref. [7] 146

3 D. CAD Geometry Modification CAD models usually are intended to accurately represent the exact intent of the final design and often lack additional features required for simulation. Design- Modeler provides these unique simulation features like splitting surfaces for applying loads, defining welds or creating regions around models that represent air is shown in Figure 2. A. Patch Surfaces Created On Larger Areas For Applying Boundary Conditions B. Geometry Representing The Air Around An Electric Motor Armature Is Created For A Later Field Analysis. V. AUTOMATION OF THE JIB CRANE DESIGN PROCEDURE BY PARAMETRIC MODELING USING ANSYS WORKBENCH Processes and methods used in jib crane design are subjected to significant changes after the recent developments in mechanical engineering and computer technology. However it is clear that the jib crane mechanisms (Hoisting, Locomotion and others) are composed of similar mechanical and electrical components, which are independent of the jib crane type when crane design procedures in practice and jib crane Mechanisms are examined closely. Starting from this fact, an overall component tree of jib cranes is developed to illustrate the use of similar mechanical and electrical components in jib crane mechanisms of different types. Although the mechanical and electrical components of different mechanisms are varying in type, size, and mechanical and electrical properties, all of these components are designed by using similar computational procedures and rules. All subsystems of a jib crane (as an engineering system) are assemblies of these components; hence design procedures of jib crane mechanisms show close similarities. These mechanical and electrical components, which have well identified design procedures, are called "Design Modules" of jib cranes. Main design modules of jib cranes are determined from the available design procedures and component tree of jib cranes. Design modules are so identified that an "Independent Design Procedure" is defined clearly for each of the design modules. Collection of the developed "Independent Design Procedures" (IDP) covers any jib crane design procedure completely, for both design calculation and/or selection of the design modules. This feature enables designers to use their own preferred parametric modeling values in their design. Ref. [2] Ansys Workbench simulation strategy for Parametric-Driven Design is Figure 2. Cad Geometry Modification CAD models also may contain much more detail that the simulation process requires or the detail may not be in the right form. Design-Modeler enables tasks like CAD feature deletion; surface extraction from a solid body, suppressing parts and merging parts into one body is shown in Figure 3. Ref. [7] Figure 3. Solid Geometry of an Assembly & Surface Geometry Extracted In Design Modeler for Same Assembly 147 A. Parametric Architecture Within ANSYS Workbench Associativity with CAD systems means that design changes can be made to the CAD model without having to reapply loads and/or supports. As normal CAD models may be defined with multiple parameters, the engineer can filter through those parameters which he/she is allowed to modify while suppressing others from any optimization work. All other parameters that may affect the performance of the design, including material properties and loading conditions, can also be defined in the same way (Figure 4). In many cases, this data can also be transferred from the CAD system. Consequently, a master simulation model can be set up once from which all design changes can be investigated quickly and efficiently. Ref. [7] In practice, engineers do not always have access to perfect CAD models for parametric-driven simulation. Consequently, capabilities have been included to enable CAD geometry to be tuned for the purpose of analysis without breaking the bi-directional integration. In other cases, CAD geometry has not been created with

4 parameterisation in mind, or only legacy faceted data is available. Again, ANSYS have developed tools to Re- Parameterize models and enable design modifications within an optimization framework. Figure 4. Parametric Definition of Material Data B. How We Can Deal With Non-Parametric CAD Simulation often demands modeling operations, such as mid-surfacing and de-featuring, beyond the intrinsic CAD design. Such capabilities are either lacking in CAD systems or Workbench application that prepares CAD designs for the purpose of high quality FEA or CFD without breaking the parametric link. Furthermore, new parametric features can be implemented in a fashion that is not optimum for performing simulation related functions. Furthermore, the user may wish to maintain a divide between CAD models for the purpose of detailing and manufacturing, with geometry required for simulation. Design-Modeler is an added to a static CAD model. Figure 5 shows how parametrically defined angle can be created / modified within an existing design. Figure 5. Example of How Parametrically Defined Angle Can be Modified In Cad Model 148

5 C. How We Can Deal With Non-Parametric Legacy Mesh In some cases, the CAD designer may want to optimize their design but have not yet created a parametric 3D geometry. By working with faceted data rather than a solid model, mesh morphing technology allows parameterization of models created from CAD data, nonparametric geometry data such as IGES or STEP, or mesh files such as NASTRAN, ABAQUS or ANSYS data files (Figure 6). Ref. [7] Figure 6. Recreating Geometry & Parameterising a Legacy Mesh VI. CONCLUSION Jib Cranes vary widely in configuration, capacity, mode of operation, intensity of use, working environment and cost. The variety of forms, operating conditions, environmental factors make the design of jib cranes challenging. Usually a new design need arises when existing cranes do not meet the requirements for a new application. However, in most of the cases the required knowledge on configuration and structure of a jib crane can be obtained from previously accumulated technical information. The technical information is generally standardized. Besides that, the available jib crane components are also well standardized all over the world and suitable for computer automated design procedures. Since jib Crane design procedures are highly standardized, main effort and time spent in jib crane design procedures are for the interpretation and use of the parametric modeling. As a result of these facts, a computer-automated access to the available standards is required for the completeness and efficiency of any design automation for jib crane design. Ref. [6] In general, some of the main benefits of the automated design include the following: Greater consistency of design; this makes manufacturing and field service easier. Ability to explore more alternatives; because design can be created in a shorter time, it allows designers to study more alternatives. Retention of design expertise; Movements of engineering personnel can cause difficulties for engineering organizations. Automating the design process can capture and document this design expertise. ACKNOWLEDGMENT The author wishes to thank my respected guide & Head Department of Production Engineering Dr. B. M. Dabade, Director Dr. S R. Kajle, for providing necessary facilities. This work was supported in part by a grant from Shri Guru Gobind Singhji Institute of Engineering & Technology Nanded, Maharashtra, India. REFERENCES [1] Baker J. Cranes in Need of Change, Engineering, v. 211, n. 3, p [2] Basu A., Majumdar A. K., Sinha S., An Expert System Approach to Control System and Analysis, IEEE Trans. on Systems, Mans and Cybernatics, v. 18, n. 5, pp , [3] Erden Z., Erkan M. and Erden A., A Computer Based Design Support System for Automate Access to the F. E. M. Rules in a Crane Design Procedure, Proceedings of the 7th International Machine Design and Production Conference, pp , Ankara, Turkey [4] Gupta T. An Expert System Approach in Process Planning: Current Development and its Future, Computers and Engineering, v. 18, n. 1, pp , [5] Marchese P. J. and Rice R. F., Trends in Equipment Design and Controls for Heavy Duty Industrial Overhead Traveling Cranes, Iron and Steel Engineer, v. 51, n. 9, p. 66, [6] Unsal (Erden), Z. and Erden, A., Computer Automated Access to the F.E.M. Rules for Crane Design, Proceedings of the International Conference on Engineering Software, pp , Stafford, UK [7] Ansys Workbench 11.0 help library