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The purpose of this study is to present a simplified analytical method to estimate ground lateral displacement due to excavation. Excavations of foundation pit will inevitably lead to soil movements that may adversely impact surrounding facilities or structures. Thus, estimation of the ground displacement induced by excavation is essential in engineering practice.

Based on a theory of elastic mechanics, a simplified analytical method for predicting the ground lateral displacement resulting from foundation pit excavation is proposed.

As the distance from the soil to the supporting structure increases, the maximum ground lateral displacement decreases nonlinearly but at a reduced rate. Poisson’s ratio of soil has a mild influence on the ground lateral displacement, whereas the influence of the supporting structure’s deflection modes is significant.

The advantage of the proposed simplified analytical method lies in that it considers the supporting structure’s arbitrary deflections, giving it wider practical applicability than previous methods.

The purpose of this paper is to explore the possibility of combining additive manufacturing (AM) with topology optimization to generate support structures for addressing the challenging overhang problem. The overhang problem is considered as a constraint, and a novel algorithm based on continuum topology optimization is proposed.

A mathematical model is formulated, and the overhang constraint is embedded implicitly through a Heaviside function projection. The algorithm is based on the Solid Isotropic Material Penalization (SIMP) method, and the optimization problem is solved through sensitivity analysis.

The overhang problem of the support structures is fixed. The optimal topology of the support structures is developed from a mechanical perspective and remains stable as the material volume of support structures changes, which allows engineers to adjust the material volume to save cost and printing time and meanwhile ensure sufficient stiffness of the support structures. Three types of load conditions for practical application are considered. By discussing the uniform distributive load condition, a compromise result is achieved. By discussing the point load condition, the removal work of support structures after printing is alleviated. By discussing the most unfavorable load condition, the worst collapse situation of the printing model during printing process is sufficiently considered. Numerical examples show feasibility and effectiveness of the algorithm.

The proposed algorithm involves time-consuming finite element analysis and iterative solution, which increase the computation burden. Only the overhang constraint and the minimum compliance problem are discussed, while other constraints and objective functions may be of interest.

Compared with most of the existing heuristic or geometry-based support-generating algorithms, the proposed algorithm develops support structures for AM from a mechanical perspective, which is necessary for support structures particularly used in AM for mega-scale construction such as architectures and sculptures to ensure printing success and accuracy of the printed model.

With the rapid development of AM, complicated structures result from topology optimization are available for fabrication. The present paper demonstrates a combination of AM and topology optimization, which is the trend of fabricating manner in the future.

This paper remarks the first of attempts to use continuum topology optimization method to generate support structures for AM. The methodology used in this work is theoretically meaningful and conclusions drawn in this paper can be of important instruction value and practical significance.

This study aims to further the understanding of support structures and the likely impacts on maraging steel MS1 parts fabricated by selective laser melting (SLM) at 45°, 60° and 75° building angles.

Two groups of samples, one group with support structures and the other group without support structures, were designed with the same specifications and printed under the same conditions by SLM at 45°, 60° and 75° building angles. Differences in dimensional accuracy, surface roughness, Vickers microhardness, residual stress and microstructure were compared between groups.

The results showed that with support structures, more accurate dimension and slightly higher Vickers microhardness could be obtained. Larger compressive stress dominated and was more uniformly distributed on the supporting surface. Without support structures, the dimension became more precise as the building angle increased and alternating compressive and tensile stress was unevenly distributed on the supporting surface. In addition, the surface roughness of the outer surface decreased with the increase of the built angle, regardless of the support structures. Furthermore, whether the building angle was 45°, 60° or 75°, the observed microstructures revealed that the support structures altered the orientation of the molten pool and the direction of grain growth.

This paper studies the influence of support structures on the workpieces printed at different building angles. Support structures affect the residual stress distribution, heat dissipation rate and microstructure of the parts, and thus affecting the printing quality. Therefore, it is necessary to balance the support strategy and printing quality to better apply or design the support structures in SLM.

Two-level support with Level 1 consisting of a set of beams and Level 2 consisting of a tree-like structure is an efficient support structure for extrusion-based additive manufacturing (EBAM). However, the literature for finding a slim two-level support is rare. The purpose of this paper is to design a lightweight two-level support structure for EBAM.

To efficiently solve the problem, the lightweight design problem is split into two subproblems: finding a slim Level 1 support and a slim Level 2 support. To solve these two subproblems, this paper develops three efficient metaheuristic algorithms, i.e. genetic algorithm (GA), genetic programming (GP) and particle swarm optimization (PSO). They are problem-independent and are powerful in global search. For the first subproblem, considering the path direction is a critical factor influencing the layout of Level 1 support, this paper solves it by splitting the overhang region into a set of subregions, and determining the path direction (vertical or horizontal) in each subregion using GA. For the second subproblem, a hybrid of two metaheuristic algorithms is proposed: the GP manipulates the topologies of the tree support, while the PSO optimizes the position of nodes and the diameter of tree branches. In particular, each chromosome is encoded as a single virtual tree for GP to make it easy to manipulate Crossover and Mutation. Furthermore, a local strategy of geometric search is designed to help the hybrid algorithm reach a better result.

Simulation results show that the proposed method is preferred over the existing method: it saves the materials of the two-level support up to 26.34%, the materials of the Level 1 support up to 6.62% and the materials of the Level 2 support up to 37.93%. The proposed local strategy of geometric search can further improve the hybrid algorithm, saving up to 17.88% of Level 2 support materials.

The proposed approach for sliming Level 1 support requires the overhanging region to be a rectilinear polygon and the path direction in a subregion to be vertical or horizontal. This limitation limits the further material savings of the Level 1 support. In future research, the proposed approach can be extended to handle an arbitrary overhang region, each with several choices of path directions.

The details of how to integrate the proposed algorithm into the open-source program CuraEngine 4.13.0 is presented. This is helpful for the designers and manufacturers to practice on their own 3D printers.

The path planning of the overhang is a critical factor influencing the distribution of supporting points and will thus influence the shape of the support structure. Different from existing approaches that use single path directions, the proposed method optimizes the volume of the support structure by planning hybrid paths of the overhangs.

The purpose of this paper is to design a lightweight tree-shaped internal support structure for fused deposition modeling (FDM) three-dimensional (3D) printed shell models.

A hybrid of an improved particle swarm optimization (PSO) and greedy strategy is proposed to address the topology optimization of the tree-shaped support structures, where the improved PSO is different from traditional PSO by integrating the best component of different particles into the global best particle. In addition, different from FEM-based methods, the growing of tree branches is based on a large set of FDM 3D printing experiments.

The proposed improved PSO and its combination with a greedy strategy is effective in reducing the volume of the tree-shaped support structures. Through comparison experiments, it is shown that the results of the proposed method outperform the results of recent works.

The proposed approach requires the derivation of the function of the yield length of a branch in terms of a set of critical parameters (printing speed, layer thickness, materials, etc.), which is to be used in growing the tree branches. This process requires a large number of printing experiments. To speed up this process, the users can print a dozen of branches on a single build platform. Thereafter, the users can always use the function for the fabrication of the 3D models.

The proposed approach is useful for the designers and manufacturers to save materials and printing time in fabricating the shell models using the FDM technique; although the target is to minimize the volume of internal support structures, it is also applicable to the exterior support structures, and it can be adapted to the design of the tree-shaped support structures for other AM techniques such as SLA and SLM.

Additive manufacturing based on arc welding is a fast and effective way to fabricate complex and irregular metal workpieces. Thin-wall metal structures are widely used in the industry. However, it is difficult to realize support-free freeform thin-wall structures. This paper aims to propose a new method of non-supporting thin-wall structure (NSTWS) manufacturing by gas metal arc welding (GMAW) with the help of a multi-degree of freedom robot arm.

This study uses the geodesic distance on the triangular mesh to build a scalar field, and then the equidistant iso-polylines are obtained, which are used as welding paths for thin-wall structures. Focusing on the possible problems of interference and the violent variation of the printing directions, this paper proposes two types of methods to partition the model mesh and generate new printable iso-polylines on the split meshes.

It is found that irregular thin-wall models such as an elbow, a vase or a transition structure can be deposited without any support and with a good surface quality after applying the methods.

The experiments producing irregular models illustrate the feasibility and effectiveness of the methods to fabricate NSTWSs, which could provide guidance to some industrial applications.

Recent technological and social changes have challenged manufacturing firms to remain competitive in increasingly dynamic markets. A way of facing these challenges is to foster organizational structures that encourage creativity. Although the general importance of organizational creativity for market success is undeniable, few studies on manufacturing firms have provided a nuanced view of how this relationship is affected by firm-external factors (e.g. different levels of market dynamism) and whether and how this leads to greater market success.

This research uses survey data from 255 chief executive officers (CEOs) and top managers of manufacturing firms in Germany. The authors performed different regression analyses to test for direct, mediation, moderation and moderated mediation effects.

The findings show that, in highly dynamic markets, organizational support for creativity indeed helps manufacturing firms to remain competitive by positively influencing firms' innovation performance, which subsequently results in improved market performance. By contrast, in markets with low dynamism, organizational support for creativity has no impact on firms' innovation and market performance.

From a theoretical perspective, this study introduces market dynamism as a novel, so-far underexplored firm-external factor that moderates the relationship between organizational support for creativity and innovation and market performance. This research thus enhances the understanding of the dynamics of organizational creativity and its effects on innovation and market performance in an organizational context of manufacturing firms.

In general, this research emphasizes the importance of establishing a creativity-supporting environment to enhance innovation and market performance. Most importantly, this relationship depends on whether firms are active in highly dynamic or stable markets. Managers should thus consider the level of (future) market dynamism when making decisions about creativity-supporting work environments.

This research provides novel insights into how organizational support for creativity influences innovation and market performance in the manufacturing industry and introduces market dynamism as an important moderating factor.

Being mindful of the importance of organizational structure and organizational culture for knowledge management in companies, the purpose of this study is to investigate the organizational prerequisites for creating and sharing knowledge. The goals are to determine whether and to what extent the attributes of organic structure contribute to the creation and sharing of knowledge and to show that an organizational culture which supports knowledge stimulates the processes of knowledge creation and sharing.

The data for the empirical study was obtained through a survey of 150 respondents, employed in 30 companies from several industries, in the Republic of Serbia. The questionnaire was adapted to the needs of the study and was developed based on the theoretical knowledge and findings of several previous studies on processes of knowledge creation and knowledge sharing. A regression method was used to test all hypotheses.

The results show that both the organic structure and the organizational culture that support knowledge have positive effects on knowledge creation, while knowledge sharing is positively influenced only by the knowledge supporting culture of an organization.

This study contributes to organization studies and knowledge management theory because of the holistic approach taken with regards to the issue involved and the fact that it takes into account a large number of the significant characteristics of organizational structure and culture that are relevant to knowledge management processes. The findings could prove useful to managers when structuring an organization and shaping its culture to enhance knowledge management.

Teachers play a vital role in the structure of their classrooms. Part of this structure is having a clear understanding of the importance of not only supporting their students, but also the teacher assistants/support staff with whom they collaborate. Providing teacher assistants/support staff with guidance, information on student needs and classroom structures, team-building strategies, training, and supervision sets the stage for a positive climate for collaboration, teamwork, and learning. Consequently, teachers should be proactive and diligent to ensure high-quality training and supervision for teacher assistants/support staff, as this will have a direct impact on the services and learning opportunities being provided to the students.

As the technology matures, design rules for additive manufacturing (AM) can help ensure manufacturability, which can be viewed as compatibility between designs and the fabrication processes that produce those designs. Though often informal, current rules frequently provide direct guidelines or constraints for designing AM-destined parts. The aim of this paper is to standardize how design rules are developed and conveyed in AM by presenting design rules as sets of modular components and associated formalisms.

The proposed methodology decomposes fundamental geometry, process and material relationships into reusable modules. Independent of context, modular representations can be more easily interpreted and efficiently implemented than current one. By providing task-specific context, components are specialized to represent process-specific parameters for different AM builds and processes. This method of specialization enables designers to reconfigure design rules, rather than create new rules from scratch, thus preserving fundamental AM principles while supporting customization and explicit representation.

Modularity and formalisms provide both structure for the generalizations and a means to tailor that structure for a specific process, machine or build. The adoption of principles and formalisms that allow us to modify, extend, reconfigure or customize generalized rules as needed – instinctively and deliberately.

This method of specialization enables designers to reconfigure design rules, rather than create new rules from scratch, thus preserving fundamental AM principles while supporting customization and explicit representation.