Clamp links: A novel type of reciprocal frame connection

Reciprocal frames (RFs) are complex structural systems based on mutual support between elements. One of the main challenges for these structures is achieving geometrical complexity with ease for assembly. This paper describes the development of a new type of connection for RF that uses a single bolt to fix a whole fan. The method used was the Research Through Design, using algorithmic modelling and virtual and physical prototyping. After the exploration of different alternatives, the connection selected was structurally evaluated with a 3D solid finite element analysis (FEM) software and a 2D bar parametric model. Finally, a full-scale pavilion was built as a proof-of-concept. A total of 47 connections were fabricated using four 3D-printed templates combined with a hand router. The construction allowed us to draw conclusions on the connection design and the assembly method, and the process as a whole can contribute to the development of new structural links and production methods.

A Component-Based Model for Novel Modular Connections with Inbuild Component

A modular steel structure building has obvious advantages in reducing construction period and protecting the environment due to its unique construction method, so it is widely used in modern construction. However, the modular building connection design and modeling are mostly based on the traditional connection research results. To address this issue, the paper developed a component-based model for novel modular connections with an inbuild component. First of all, the comprehensive parameter study was implemented using elaborate finite element models. Then the component-based model for novel modular connections was developed, and the force-deformation response of each component was determined using the finite element method. Thirdly, assembly of all components to overall rotational joint and the simplified finite element model of modular connections was obtained. Finally, comparison between simplified and refined finite element was conducted, the results showed that the proposed model can predict the mechanical behavior of modular building connections within the acceptable margin of error.

Nuts & Bolts: An exploration of design for deconstruction and component re-use in engineered timber construction

<p><b>This research is fuelled by the ever-increasing impact of global pollution and climate change, and the role the construction industry plays in it. Vast amounts of construction waste, needless manufacturing of single-use and composite products, and poor construction practices culminate in a linear economy model on which the world operates. It is a problem that can no longer be ignored and must be rectified. This research aims to develop and propose a construction system suitable for deconstruction and continued component reuse, using engineered timber products available in today’s market. The system will be tested against several implementations across a variety of building scales. This research has the intention of enabling component reuse for a circular economy. A circular economy minimises waste produced. Less waste is good.</b></p> <p>The resulting design proposal is a modular and prefabricated braced frame construction system to suit large and small scales, with removable foundations and adaptive spatial planning. Effective separation of building layers is achieved to allow for access, maintenance, and simple disassembly. Traditional Japanese timber joining techniques have also been researched and used to influence component connection design for deconstruction. This research eliminates irreversible fixings such as adhesives, nails, and screws. The system is then tested across commercial, residential, and small-scale implementations to test its feasibility.</p> <p>It will serve as a case study that questions how we think of buildings and value their components. It aims to enable the same components to be useful across multiple building scales, minimising redundancy and waste.</p>

Nuts & Bolts: An exploration of design for deconstruction and component re-use in engineered timber construction

<p><b>This research is fuelled by the ever-increasing impact of global pollution and climate change, and the role the construction industry plays in it. Vast amounts of construction waste, needless manufacturing of single-use and composite products, and poor construction practices culminate in a linear economy model on which the world operates. It is a problem that can no longer be ignored and must be rectified. This research aims to develop and propose a construction system suitable for deconstruction and continued component reuse, using engineered timber products available in today’s market. The system will be tested against several implementations across a variety of building scales. This research has the intention of enabling component reuse for a circular economy. A circular economy minimises waste produced. Less waste is good.</b></p> <p>The resulting design proposal is a modular and prefabricated braced frame construction system to suit large and small scales, with removable foundations and adaptive spatial planning. Effective separation of building layers is achieved to allow for access, maintenance, and simple disassembly. Traditional Japanese timber joining techniques have also been researched and used to influence component connection design for deconstruction. This research eliminates irreversible fixings such as adhesives, nails, and screws. The system is then tested across commercial, residential, and small-scale implementations to test its feasibility.</p> <p>It will serve as a case study that questions how we think of buildings and value their components. It aims to enable the same components to be useful across multiple building scales, minimising redundancy and waste.</p>

The Microbial Neck: A Biological Review of the Various Implant–Abutment Connections

Aim: This study reviews the importance of selecting implant systems with connection designs that ensure better long-term prognosis of the prosthesis, thus placed. Materials and Methods: An electronic search on the PubMed database was done using MeSH keywords (“dental implant OR abutment OR connection AND microleakage OR bone loss”) to review English language articles published since the year 2011, which compared the crestal bone levels and microleakage around various implant–abutment connection designs (external hex, internal hex, and Morse taper). The search screened for articles on human trials and in vitro studies to be included within the review. Results: Based on the inclusion and exclusion criteria applied to the preliminary search, a total of four articles were included in the review for evaluating the influence of connection type on peri-implant bone loss, while nine articles were included to study the influence on bacterial leakage across the implant–abutment interface. Conclusion: Based on the studies reviewed, the conical connection design proved to be the most biologically stable junctional geometry because of the better microbial seal and the lesser micromovement observed in these types of implants during functional loading. Moreover, this review even emphasizes the need for more longitudinal clinical trials to assess the microbial seal of these connection designs within the actual oral environment to evaluate long-term changes in the peri-implant tissues, and subsequently even factor the prognosis of the planned prosthetic intervention.

Comparing the Fracture Resistance and Modes of Failure in Different Types of CAD/CAM Zirconia Abutments with Internal Hexagonal Implants: An in Vitro Study

3 groups of zirconia abutments (n=3) made of different connection design or manufacturers were investigated (All-Zr, ASC-Zr and AM-Zr groups). All-electric dynamic test instrument was used to place static loading on specimen with a crosshead speed set at 1 mm/min. One-way analysis of variance (ANOVA) and post hoc Tukey tests (α=.05) were used for statistical evaluation. The mean fracture resistance was 258.21±68.60 N for All-Zr group, 360.55±29.66 N for ASC-Zr group, and 341.45±25.97 N for AM-Zr group. There was no significant difference in fracture resistance between the 3 groups (1-way ANOVA, P = 0.10). The modes of failure among the 3 types of abutments are different. The All-Zr group showed an oblique fracture line starting from the buccal aspect at the region of the implant platform. While in the ASC-Zr group and the AM-Zr group showed a relatively horizontal fracture line with greater distance from implant platform. The titanium inserts cannot significantly improve the fracture resistance of the zirconia abutment. However, they may alter the modes of failure, allowing buccal fracture surfaces of the zirconia abutments to be placed away from the implant platform, thereby protecting the implant-abutment connection.

Fit for Purpose Connection Design for Drilling Operations in Size Constrained Tubular

Drilling out or working within small sizes of casing and liners requires the use of a drill string with small outside diameter tool joints to fit inside the casing/liner bore and, at the same time, a large enough connection internal diameter to pump actuating balls inside the drill string when needed. These requirements significantly limit the available options that can be used. Historically, a drill pipe double shoulder connection with a 3⅛-in. outside diameter (OD) has been used for such operations, as it allows for multiple makeups and breakouts before it needs to be repaired. This is a great improvement compared to using small tubing premium connections that are somewhat limited on the number of makeups. However, the geometry constraints are such that the thin material envelope leads to torsional weakness in the connection, resulting in a higher than expected recut rate as connections can be overtorqued downhole in operation. A research and development (R&D) project was commissioned to improve the connection performance significantly to mitigate the downhole overtorque. Exploring the acceptable connection envelope limits allowed for a slightly reduced internal diameter (ID) when compared to the previously used connection. The team considered different thread designs and decided to use the one that would provide the highest torque. The design process was then followed to develop and qualify a well-balanced connection. The design validation was performed at an engineering technology center in Houston, Texas, where samples were destructively tested to compare the actual capacity of the new connection against the calculated values. It was confirmed that the torsional strength of the new design meets and exceeds the theoretical value, an improvement of at least 85% over the previously used connection, and a first string was built. It was subsequently deployed in the field and the recut rate was monitored to establish that the objective of delivering a connection capable of higher torque was indeed met to resist the downhole overtorque.

EVALUATION OF LOAD-BEARING CAPACITY OF THE STEEL CONSTRUCTION JOINTS ON THE BASIS OF COMPONENT METHOD

Connections are essential in every kind of steel constructions. Structure is a constructed assembly of joints separated by members which implies the importance of connections. Three basic parameters describe the behavior of connections: strength, stiffness and ductility, and the mechanical behavior of steel joint in those terms are complex phenomena. It must be said that absence in current Ukrainian design codes rules for the load capacity calculation of steel constructions connections led to some difficulties in project decisions. On the basis of component method, which lay in the EC3 design codes load capacity estimation of beam to column connection was made. According to component method beam to column connection divided into basic components. EN 1993 -1-8 provides a good overview of different components. Most important components for bolted steel joints are the plates and bolts which both are considered by the design of a T-stub through the “Equivalent T-stub in tension”. The procedure of load capacity calculation used yield line formulations to determine resistance of the following basic components: column flange in bending, end plate in bending, column flange in bending, column web in tension, column web in compression, beam flange in compression. Failure by this method is described by yield-line models depending on geometry of plates and bolts. Obtained analytical results were compared with the results obtained by means of specialized software and it shown their adequacy. It must be noted that presented in EC3 calculation algorithm of beam to column connection is time consumable for domestic designer also designer must have knowledge about features of connection design in countries of EC. The choice of design procedure depends on the time effort and thereby to the designer preferences.