Enabling Cost-Based Support Structure Optimization in Laser Powder Bed Fusion of Metals

Support structures are essential to laser powder bed fusion (PBF-LB/M). They sustain overhangs, prevent distortion, and dissipate process-induced heat. Their removal after manufacturing is required, though, increasing the overall costs. Therefore, optimization is important to increase the economic efficiency of PBF-LB/M. To enable optimization focused on the support structures’ costs, a cost model is developed. The whole production process, including the design, manufacturing, and post-processing of a part, is considered by deriving formulas for the individual costs. The cost model is applied to a previously developed benchmark procedure. Additionally, a case study investigating different support layout strategies is conducted.

Changes in Tenant Layout in an Effort to Increase Turnover at the Convention Hall Culinary Center (CH-Kuliner) Surabaya

This study examined the impact of layout changes or re-layout on the turnover of the tenants at the Culinary Center Convention Hall (SKCH) Surabaya. The aspects studied concerned spatial purpose and layout functions. Spatial purpose included area expansion, ease of access and lighting, and equalization considerations for tenants. Layout functions included the variable of SKCH’s location. The four variables support layout changes, thus increasing the turnover of the tenants in SKCH. A descriptive qualitative method was used. The study included all 25 tenants who were in SKCH before and after the re-layout. Each aspect indirectly brought a positive influence on the increase in turnover of the majority of tenants at SKCH, with the purpose aspect of spatial layout increasing the turnover of 64% of tenants and the aspect of layout function increasing the turnover of 92% of tenants. Keywords: layout change, culinary center, spatial purpose, layout functions, tenant, stand, consumer, re-layout

Integrated component-support topology optimization for additive manufacturing with post-machining

PurposeThe purpose of this paper is to communicate a method to perform simultaneous topology optimization of component and support structures considering typical metal additive manufacturing (AM) restrictions and post-print machining requirements.Design/methodology/approachAn integrated topology optimization is proposed using two density fields: one describing the design and another defining the support layout. Using a simplified AM process model, critical overhang angle restrictions are imposed on the design. Through additional load cases and constraints, sufficient stiffness against subtractive machining loads is enforced. In addition, a way to handle non-design regions in an AM setting is introduced.FindingsThe proposed approach is found to be effective in producing printable optimized geometries with adequate stiffness against machining loads. It is shown that post-machining requirements can affect optimal support structure layout.Research limitations/implicationsThis study uses a simplified AM process model based on geometrical characteristics. A challenge remains to integrate more detailed physical AM process models to have direct control of stress, distortion and overheating.Practical implicationsThe presented method can accelerate and enhance the design of high performance parts for AM. The consideration of post-print aspects is expected to reduce the need for design adjustments after optimization.Originality/valueThe developed method is the first to combine AM printability and machining loads in a single topology optimization process. The formulation is general and can be applied to a wide range of performance and manufacturability requirements.

Role of Positive Emotions in Organisational Coping

The broaden-and-build theory of positive emotions postulated by Barbara L. Fredrickson proposes that emotions like joy, interest, contentment, and love enable an individual to broaden his/her patterns of thinking and acting, which in turn build the personal coping resources, whether intellectual, physical, social, or psychological, by way of creating novel ideas, actions or social relationships. This paper is a review of 15 empirical studies carried out during 1998-2012 that support the contributions of this theory to the creation of a healthy workplace by fostering positive emotions in employees. Positive emotions were found to be pivotal in enhancing employee performance, encouraging innovation and creativity that result in sustainable business practices, helping organizations make good decisions, facilitating work-flow and motivation, developing authentic and charismatic leadership styles, job enrichment, better team performance, and satisfactory customer relations. A link between positive emotions and an upward spiral of personal and organizational resources has also been established where positive self-evaluation, development of resilience, a climate of social support, layout of clearer goals, high quality social-interaction, good health and productivity of workers have been found to promote effective coping.

Multi load-transmitting device based support layout optimization for large fuselage panels in digital assembly

A large fuselage panel is always connected to a full-scale shape-preserving bracket to enhance its stiffness in digital assembly processes and reduce assembly deformation induced by factors such as gravity. However, the full-scale shape-preserving bracket’s characteristics, such as large size and weight, usually result in a complex installation process and high maintenance costs. A method for optimizing a multi load-transmitting device based discrete support layout is presented in this paper. By constructing finite element model including the fuselage panel and LTDs, the panel’s strain energy under different support layout parameters is obtained according to the principle of mixed uniform design. Using the method of partial least squares regression, the mathematical relationship between the strain energy and the support layout parameters is established, which is then used to obtain the optimum multi LTD based support layout. Furthermore, by comparing the panel deformation under the optimum multi LTD based support with that under the full-scale shape-preserving bracket-based support, we conclude that the optimum multi LTD based support can not only suppress panel deformation effectively, but also keep the panel’s stiffness comparable to that under the full-scale shape-preserving bracket-based support.