Experimental Analysis and FEA of Friction Stir Welding on Aluminium Plates

An experimental study and a numerical simulation of friction stir welding (FSW) process on aluminum 6064 plates is presented. The numerical analysis is performed using finite element technique with LsDyna software and the Aleatory Lagrangian Eulerian (ALE) formulation. Input parameters on the FEM are the mechanical properties of the aluminum 6064 as workpiece and H13 steel properties as the tool. The finite element analysis results shown Von Mises stresses and plastic strain developed during the process. An experimental analysis was conducted with the variation of process parameters and the specimens obtained were evaluated by x-ray inspection, tensile tests, and hardness measurements.

Simulation Driven Processing Function Development, Offering and Operation

In today’s industry, functional provision is becoming more and more important, necessitating increased simulation support. In this paper, the objective is to present a modeling and simulation approach for simulation-driven design (SDD) to support function development. The scope of this paper is simulation support for developing hardware equipment used in processing industry. The research is founded on industrial needs identified through two parallel interview-based studies in the Swedish process industry. Both companies explore doing business with functional products rather than hardware, in scenarios where the responsibility for and availability of the functions may remain with the service provider. One as-is and one future (to-be) scenario are presented. A decomposition of a general processing function (applicable to both companies) describes how the companies transfer machine input to output specifications. The decomposition includes customer and provider value and the paper demonstrates, as part of the results and based on the SDD approach, how that value may be increased through evaluation and prioritization. Additionally, the SDD approach shows that it is possible to identify a set of solutions which meet the specified requirements, supporting evaluation and prioritization of business offers and activities.

Multi-Period Turning Interpolation Algorithm for High-Speed Machining of Continuous Line Segments With Limited Acceleration, Jerk and Chord Error

In this paper, a multi-period turning interpolation algorithm, with real-time look-ahead scheme based on S-curve control method, is presented. In this interpolation algorithm, the geometric precision and the dynamic performance are both satisfied. The machining efficiency is improved by multi-period turning transition, and the precision is also improved by S-curve control method. The computational efficiency of this algorithm meets the need of real-time machining. In addition, there is no accumulated error. At last, this algorithm is verified the validation by the experiments on 3-axis CNC machine.

Mitigation of Pore Generation in Laser Welding of Magnesium Alloy AZ31B in Lap Joint Configuration

Magnesium, as the lightest structural metal, has been widely used in the automotive and aerospace industries. Porosity is the main issue in the welding of magnesium alloys and can be caused by surface coatings, hydrogen gas, pre-existing porosity, the collapse of an unstable keyhole and vaporization of alloying elements. In this study, the effect of the oxide layer on pore generation in the welding of AZ31B-H24 magnesium alloy is investigated. A fiber laser with a power of up to 4 kW is used to weld samples in a lap joint configuration. Two groups of samples are studied: as received (AR) surfaces (where an oxide layer remains on the surface) and treated surfaces. The surface treatment includes two techniques: mechanical removal (MR) and the use of a plasma arc (PA) as a preheating source. Also, a separate set of experiments are designed for preheating samples in a furnace in order to investigate whether the pore mitigation effect of a plasma arc is caused by preheating. Observations include a weld bead profile achieved through optical microscopy, chemical compositions tested by Electron Dispersive Spectroscopy (EDS), and mechanical properties measured with a tensile test. The results obtained show that the preheating effect of a plasma arc procedure can effectively mitigate pore generation. The tensile-shear results reveal that PA samples have a higher strength than other groups of samples.

Polyhedral Space Curve Meshing Reducer With Multiple Output Shafts

In recent years, a gear named Space Curve Meshing Wheel (SCMW) has been invented based on the meshing theory of space curves instead of classic space surfaces. Well improved in many aspects after its invention, it has been applied within the Space Curve Meshing Reducer (SCMR). The design method of an invention named polyhedral SCMR is presented in this paper. With single input shaft and multiple output shafts, this SCMR has advantages like compact structure, flexible design and low cost. It is characterized by the application of the SCMW group containing one driving wheel and several driven wheels, whose rotation axes are concurrent at a point and radiate in polyhedral directions. A SCMW group can form a single-stage SCMR, while SCMW groups connected can form a multiple-stage SCMR. In this paper, geometric parameters of the polyhedral SCMR are defined, design formulas are derived, and an example is provided to illustrate the design process.

Influence of Tool Holder Material on Interfacial, Insert and Tool Holder Temperatures During Turning Operation of Gray Iron

Usually studies related to machining temperature consider a system comprised of workpiece, chip and cutting tool, the effect of tool holder material is not taken in account. However, due to its physical properties, the tool holder material, usually carbon steel, has effect in the dissipation of the heat generated. This work studies the effect of the tool holder material on the temperature distribution during the turning operation of gray iron using cemented carbide cutting tool and without cutting fluid. Five tool holders were manufactured from materials with different heat conductivity: carbon steel, stainless steel, titanium, copper and bronze. Temperatures in eight different positions in the tool holder and cutting insert were measured. The average temperature at the chip tool interface was also measured using the tool-work thermocouple method. The results showed that the measured chip tool interface temperature was less affected by the tool holder material, although the temperature distribution at the cutting tool is highly affected.

Toward a Method for Improving Product Architecture Solutions by Integrating Designs for Assembly, Disassembly and Maintenance

New customer demands and increased legislation drive business-oriented companies into new business models focusing on the entire life cycle of the product. This forces the manufacturing companies into service-oriented solutions as a compliment to the original business areas. Takata [1] postulates that “the goal is no longer to produce products in an efficient way, but rather to provide the functions needed by society while minimizing material and energy consumption”. This new situation affects the product requirements as well as product development process (PD). When focusing on the entire product life cycle, product aspects such as maintenance and repair will receive more attention since the companies will be responsible for them. In the product development process of today, especially in the automotive industry, maintenance and repair aspects (repair and maintenance methods and manuals, for example) are currently taken care of when the product is more or less fully developed. Maintenance and repair requirements are difficult to quantify in terms of core product properties (for vehicles, cost, CO2 emissions, weight, and so on). This leads to difficulties in equally considering maintenance and repair requirements while balancing vast amounts of product requirements. This paper focuses on a comparison and discussion of existing design guidelines affecting the structure and organization of parts in an assembled consumer product, such as Design for Assembly (DFA), Design for Maintenance (DFMa), Design for Service (DFS) and Design for Disassembly (DFD) methods. A tool for evaluation and analyzing product architecture as well as assemblability and maintainability is proposed.

Injection Molding Process Windows Considering Two Conflicting Criteria: Simulation Results

In this work, two criteria in conflict are considered simultaneously to determine a process window for injection molding. The best compromises between the two criteria are identified through the application of multiple criteria optimization concepts. The aim with this work is to provide a formal and realistic strategy to set processing conditions in injection molding operations. In order to keep the main ideas manageable, the development of the strategy is constrained to two controllable variables in computer simulated parts.

Hole Surface Quality and Damage When Drilling Unidirectional CFRP Composites

In this study, an experimental investigation on the drilling of unidirectional carbon fiber reinforced plastic (UD-CFRP) composite was conducted using polycrystalline diamond (PCD) tipped eight facet drill. The quality of the drilled hole surface was examined through surface roughness measurements and surface damage by scanning electron microscopy (SEM). It was found that, fiber pullout occurred in two specific sectors relative to the angle between the cutting direction and the fiber orientation. The thrust force was highly influenced by the feed rate than the cutting speed and it shows a significant variation throughout the rotation of the drill.

Effects of Within Part Variation on Measurement System Analysis

Inherent variation of the measurement system, part-to-part variation and variation arising due to the operator are considered to be the most common sources of variation in a measurement system analysis (MSA). Often errors due to within part variation are overlooked, or even worse, are assumed to be from the inherent variation of the measurement system. Understanding the sources of variation in a measurement system is important for all measurement applications. It becomes even more critical when the part used to evaluate a gage has a significant within part variation. This is an important source of measurement system error that the current procedures followed for MSA studies do not clearly or adequately address. The primary reason for this is a lack of awareness, and there are no clear guidelines on conducting a MSA study under these circumstances. A detailed analysis of the effects of within part variation on MSA is described in this paper. An improved method for conducting the MSA under these circumstances is also presented. This improved and more effective MSA takes all sources of variations into consideration.