The logistics department at the Powertrain plant of Volvo Trucks seeks to improve the efficiency within their processes. A new concept solution to the supports (pallets) that hold and carry different types of engine parts during the transportation between the sequencing area and the final assembly line called “The new dynamic pallet based on biomimicry” was presented. The concept solves the issues of the constant modifications in the pallets lead by the changes in the design of the engine parts. The main objectives of the project is the creation of a dynamic pallet, dynamic in this case translates into a modular, flexible to different geometries and scalable system, also the design solution should be inspired by nature (biomimicry) to boost a new sustainable design approach related to the values of Volvo brand. This project required iterative research regarding the principles of biomimicry and systems found in nature. Biomimicry literally means ‘the imitation of life’ but, it is better defined as a design approach to innovation which takes inspiration from systems of nature. It is provided by Volvo as the core of the project, if the result is good then there will be a push to develop new projects following this strategy seeking sustainable solutions to solve human problems. In addition, prototyping concepts from a generation of ideas to testing results were conducted to evaluate the concepts generated. The resulting concept proposal is a whole new system but preserves the functional aspects necessary to integrate the new pallet in the current logistics performance.

This diploma thesis deals with the design of a full pallet storage stacker using the FIFO method. The first part of the thesis contains a research analysis of similar competitive solutions. This is followed by a description of the created conceptual design of the storage stacker. The design includes the choice of speeds and accelerations of stacker movements, which are necessary for the calculations of the tilting, lifting and traveling mechanism. Another part of the thesis is the strength check of the lifting carriage frame. The attachment consists of the drawing documentation of the designed device.

This master’s thesis describes the structural design of pallet conveyor for the transport pallet unit between the ground floor and upper storey of warehouse buildings, according to given technical parameters. The work includes design and functional solution for driven roller track. It solves lifting of frame cage and roller track and the pallet unit, using traction gearless drive. There is used cable transfer 2:1. Frame cage is equipped with a mandatory safety gear. The design is verified strength calculations of the frame lift and frame cage. Part of the thesis is the drawing documentation.

This master’s thesis deals with design of manipulator which manipulate the types of shift forks 1/5, 2/4, 3/7 and 6/R. The machine takes parts from the belt, which transports them from mark station. Parts are moved to the straightening machine by manipulator. Straightened parts are transported on the storage place, from which are sorted into the boxes and palletized by robot. As a part of work is the proposal of alternativ solutions, selecting the best solution, the design of the chosen variant and technical calculations of the main parts of the manipulator. The work includes the accompanying drawings, assembly drawings and 3D model.

Presented are approximate finite strip methods for use in predicting elastic buckling strength of cold-formed steel columns. These methods were developed by examining elemental behavior of cross-sections in eigen-buckling analyses and validated using a large database of finite element rack-type columns with perforation patterns. The influence of perforations is accounted by reduced thicknesses related to the plate buckling coefficient and transverse web rotational stiffness in the prediction of local and distortional buckling respectively. Global buckling prediction including the influence of perforations uses critical elastic loads of an unperforated section multiplied by the ratio of weighted to gross cross-sectional moment of inertia for flexural buckling and the ratios of weighted to gross cross-sectional warping torsion constant and weighted to gross St. Venant torsional constant for flexural-torsional buckling. Concern for end-user was given and methods are presented in a way for incorporation into governing design standards. Data to support these findings are available at http://hdl.handle.net/10919/23797 / Master of Science

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The purpose of this research was to correlate the applied material properties of stretch film with its elastic properties measured in a laboratory setting. There are currently no tools available for a packaging engineer to make a scientific decision on how one stretch film performs against another without applying the film. The system for stretch wrap comparison is mostly based on trial and error which can lead to a significant loss of product when testing a new film or shipping a new product for the first time. If the properties of applied stretch film could be predicted using a tensile test method, many different films could be compared at once without actually applying the film, saving time and money and reducing risk. The current method for evaluating the tensile properties of stretch film advises the user apply a hysteresis test to a standard sample size and calculate several standard engineering values. This test does not represent how the material is actually used. Therefore, a new tensile testing method was developed that considers the film gauge (thickness) and its prestretch. The results of this testing method allowed for the calculation of the material stiffness (Bisha Stiffness) and were used to predict its performance in unit load containment. Applied stretch film is currently compared measuring containment force, which current standards define as the amount of force required to pull out a 15.2cm diameter plate, 10.1cm out, located 25.4cm down from the top and 45.7cm over from the side of a standard 121.9cm width unit load. Given this definition, increasing the amount of force required to pull the plate out can be achieved by manipulating two different stretch film properties, either increasing the stiffness of the film or increasing the tension of the film across the face of the unit load during the application process. Therefore, for this research, the traditional definition of containment force has been broken down into two components. Applied film stiffness was defined as the amount of force required to pull the film a given distance off the unit load. Containment force was defined as the amount of force that an applied film exerts on the corner of the unit load. The applied stretch film was evaluated using two different methods. The first method used the standard 10.1cm pull plate (same plate as ASTM D 4649) to measure the force required to pull the film out at different increments from the center on the face of the unit load. This measurement force was transformed into a material stiffness and film tension (which were subsequently resolved into containment force). The second, newly developed, method involved wrapping a bar under the film, on the corner of the unit load, and pulling out on the bar with a tensile testing machine. This method allowed for the direct measurement of the containment force and material stiffness. The results indicated that while some statistically significant differences were found for certain films, the material stiffness and containment were relatively consistent and comparable using either method.The use of the Bisha Stiffness to predict the applied stiffness and containment force yielded a statistically significant correlation but with a very low coefficient of determination. These results suggest that while film thickness and prestretch are key variables that can predict applied stiffness and containment force, more research should be conducted to study other variables that may allow for a better. High variability of the predictions observed were caused by the differences in film morphology between the different method of elongation (tensile vs application). This study was the first that attempted to define and correlate the tensile properties of stretch film and the applied properties of stretch film. From this research many, terms have been clarified, myths have been dispelled, formulas have been properly derived and applied to the data collected and a clear path forward had been laid out for future researchers to be able to predict applied stiffness and containment force from the elastic properties of stretch film. / Ph. D.

Industrial forklifts consist of one of the most common handling methods for pallets in warehouses and distribution centers. Pallets deflect while they are being transported by forklifts due to the weight of the unit load. Thus, most of the deflection is observed to occur on the outside edges and corners of the pallet. Several international standards are used in order to define the maximum deflection for pallet bending, including ISO 8611 and ASTM D1185. However, there is still a lack of understanding on the accuracy of these deflection limits and the exact performance of a pallet during a forklift support condition. Understanding pallet bending during forklift support condition and how it affects the stability of a unit load helps create an industry accepted deflection limit that will help to design safer and more cost-effective pallets. For this study, two chapters were proposed in order to assess pallet deflection and unit load stability. The first chapter consisted of measuring and analyzing the vibration levels for three different industrial forklifts affect by factors such as the speed, the payload of the unit load carried, sensor location, forklift type, and road conditions. The results obtained showed that the highest vibration intensity occurred at 3-4 Hz, while the highest overall Grms value observed was 0.145 G2/Hz (between 1-200 Hz). An increase in the forklift speed caused an increase in vibration intensity. In contrast, an increase in the unit load weight carried by the forklift caused a decrease in vibration intensity. Among the three forklifts studied, the gas-powered forklift had the highest vibration intensity, and all forklifts, when driven on asphalt, experienced more vibration. The second chapter of the research project consisted of evaluating pallet deflection under forklift handling conditions. These conditions included fork tines configuration (leveled and 4° angle), unit load condition (bound and unbound), pallet orientation (across width and across length), and type of handling condition (static and dynamic). The results showed that when unit loads were handled in a static condition, they survived the throughout the entire testing. However, when they were tested under a dynamic condition, and specifically, with the unbound unit loads, they did not survive the entire testing. Moreover, unit loads that were tested with the 4° angle forktines configuration tended to survive longer during the dynamic testing. For this particular case, the unit load capacity obtained based on the ISO 8611 standard was too conservative. / M.S. / Forklifts play an important role in the transportation of materials goods in the supply chain. Pallets experience vibration when they are handled by industrial forklifts. This vibration plus the combined effects mainly due to the unit load weight affects the amount that pallets bend. Thus, depending on the amount of pallet bending, they can produce unit load instability. Currently, there is a lack of understanding of how much pallet bending is acceptable. Therefore, the goal of this research was to understand the behavior of pallet bending when they are handled under forklift conditions. Two experiments were conducted in order to study pallet deflection under forklift handling conditions. The first experiment, which consisted in analyzing forklift vibration, showed that an increase in the forklift speed caused an increase in vibration intensity. In contrast, an increase in the payload of the unit load resulted in a decrease in vibration intensity. Among the three forklifts studied, the gas-powered forklift showed the highest vibration intensity. Forklifts driven on asphalt experienced more vibration in comparison to the ones driven on concrete. The second experiment, which consisted in assessing pallet deflection under a simulated forklift handling condition, showed that unit loads under a dynamic environment (vibration) increased the probability of unit load instability. Furthermore, it was observed that applying stretch wrap to a unit load decreased its instability and at the same time increases its survivability. Also, the results showed that the proposed ISO 8611 deflection limit is too conservative for this particular handling condition.

Master of Science / Pallets are used all over the world in the field of distribution. The strength values associated with a pallet have been thoroughly investigated by many different researchers; however, the stiffness values associated with pallet joints have not. The goal of this work was to investigate the stiffnesses associated with pallets joints made with lag screws and carriage bolts. It is important to understand that different materials, fastening methods, and design considerations can have a huge impact on the stiffness of the joint. This paper will discuss the various tests that were used to measure the actual stiffness of pallet joints and the results of those tests. Afterwards, the researchers detail their attempt to predict the stiffness using an equation created from the actual test data. Finally, by understanding the effects of these various factors, better pallet designs can be created that are both safer and stronger using the investigated alternative fasteners.

Notched stringer segments spliced with metal connector plates (MCPs) and pallets with spliced stringer(s) were tested in static bending in order to determine the relative effectiveness of different stringer splicing methods and under what conditions the process is or is not effective. The species tested were oak, southern yellow pine, yellow-poplar, and two combined species - oak and yellow-poplar, and oak and southern yellow pine. The metal connector plates used were 3 x 4-inch, 3 x 6-inch truss plates, and a 3 x 4-inch plug plate. The splice methods tested were a vertical splice (VS), a 45° angle splice (AS), and a vertical splice with -inch gap between segments (VSG). The results of bending tests of these specimens were compared to non-spliced whole stringers and pallets containing whole stringers. Multiple comparison, statistical methods were used to analyze all test data. An analysis of the failure locations and types of specimens was also used to analyze test results. Vertical spliced stringers with 3 x 4 and 3 x 6 inch truss plates were the best designs of those tested. Spliced stringers were an average of 112% and 74% bending strength and stiffness of new non-spliced stringer. These plates were an average of 26% stronger and 13% stiffer than the 3 x 4 inch plug plate splice stringer. There was no difference between the performance stringers spliced with 3 x 6 and 3 x 4 inch truss plate. An angle splice design and the addition of 1.25 x 6 inch truss plate on the tension side of spliced stringer did not appear to improve the strength and stiffness. A gap between segments significantly reduces splice strength and stiffness by an average of 35% and 16% respectively. When mixing stringer segment species, the performance is determined by the weaker segment. The average strength and stiffness of pallets containing spliced stringers were similar to that of pallets with whole stringers, however the variation in performance was greater when notched stringer pallets contain splices. / Master of Science