Search

This paper gives a new formulation to design adaptive structures through total energy optimization (TEO). This methodology enables the design of truss as well as tensegrity configurations that are equipped with linear actuators to counteract the effect of loading through active control. The design criterion is whole-life energy minimization which comprises an embodied part in the material and an operational part for structural adaptation during service. The embodied energy is minimized through simultaneous optimization of element sizing and actuator placement, which is formulated as a mixed-integer nonlinear programming problem. Optimization variables include element cross-sectional areas, actuator positions, element forces, and node displacements. For tensegrity configurations, the actuators are not only employed to counteract the effect of loading but also to apply appropriate prestress which is included in the optimization variables. Actuator commands during service are obtained through minimization of the operational energy that is required to control the state of the structure within required limits, which is formulated as a nonlinear programming problem. Embodied and operational energy minimization problems are nested within a univariate optimization process that minimizes the structure’s whole-life energy (embodied + operational). TEO has been applied to design a roof and a high-rise adaptive tensegrity structure. The adaptive tensegrity solutions are benchmarked with equivalent passive tensegrity as well as adaptive truss solutions, which are also designed through TEO. Results have shown that since cables can be kept in tension through active control, adaptive tensegrity structures require low prestress, which in turn reduces mass, embodied energy, and construction costs compared to passive tensegrity structures. However, while adaptive truss solutions achieve significant mass and energy savings compared to passive solutions, adaptive tensegrity solutions are not efficient configurations in whole-life energy cost terms. Since cable elements must be kept in tension, significant operational energy is required to maintain stable equilibrium for adaptation to loading. Generally, adaptive tensegrity solutions are not as efficient as their equivalent adaptive truss configurations in mass and energy cost terms.

This paper reports on experimental testing that was carried out on a prototype adaptive structure designed to counteract the effect of loading through controlled large shape changes. The prototype is 6.6 m truss equipped with 12 linear actuators which has been designed through a method that combines geometry optimization and non-linear shape control. The structure is designed to adapt into target shapes that are optimal under each load case. Shape adaptation is achieved through controlled length changes of linear actuators that strategically replace some of the structure elements. The actuator placement is optimized to control the structure into the required target shapes. This way, material utilization is maximized and thus material energy embodied is reduced. Experimental testing is carried out to verify numerical findings and investigate the feasibility of the design method. The applied load is inferred through a classification model based on supervised learning. A control algorithm based on a linear-sequential form of geometry optimization is proposed. Experimental results show that this method successfully allows for real-time shape adaptation to achieve stress homogenization under various loading conditions. Copyright (C) 2020 The Authors.

This paper presents experimental testing of a new semi-active vibration control device comprising a shape memory polymer (SMP) core that is reinforced by an SMP-aramid composite skin. This control device works as a load-transfer component that can be integrated into truss and frame structures in the form of a joint. At the material level, thermal actuation from ambient (25 degrees C) to transition temperature (65 degrees C) causes a significant 40fold increase in damping due to viscoelastic effects. At the component level, uniaxial tensile and four-point bending tests have shown that tensile strength depends primarily on the bond strength between the reinforcement skin and the structural element while flexural strength depends on the strength of the reinforcement skin fibers. Through cyclic testing, it has been observed that material viscoelasticity is beneficial to ductility and energy dissipation. When the joint core is actuated to the SMP transition temperature, axial and flexural stiffness decrease by up to 50% and 90%, respectively. The property change at material and component levels enable tuning the frequency and damping ratio at the structure level, which has been successfully employed to mitigate the dynamic response of a 1/10 scale three-story prototype frame under resonance and earthquake loadings.

External post-tensioning offers significant potential to improve the load-bearing performance of bridges. However, typical external post-tensioning systems are effective for a specific load case. This work investigates the application of an external adaptive tensioning (EAT) system for high-speed railway (HSR) bridges. The design of HSR bridges involves strict acceleration constraints, which typically results in oversizing. The EAT system comprises under-deck cables deviated by linear actuators, which enable controlling the bending moment as the load changes. Simulations are carried out on simply supported beam bridges. Results show that active control through the EAT system allows satisfying vertical acceleration limits for mid-span HSR bridges, which cannot be met otherwise without incurring a weight penalty. In addition, the cyclic stress range is significantly reduced showing the potential for fatigue-life extension.

This paper presents structural optimization techniques to design truss structures that make best use of a given stock of structural components. Still little explored, the reuse of structural components over multiple service lives has the potential to significantly reduce the environmental impact of building structures. Structural design and construction based on reuse avoids sourcing new material, it reduces superfluous waste, and requires little energy. However, designing a structure from a stock of reclaimed elements entails a change of design paradigm: in contrast to conventional design practice, the structural geometry and topology depends on element stock characteristics, e.g. available cross sections and lengths. This paper presents discrete structural optimization formulations to design truss systems from stock elements. The approach taken in this work is iterative: 1) element assignment and topology optimization are carried out, and 2) geometry optimization follows thereafter to best-fit the system geometry to the length of assigned stock elements, for instance to reduce cut-off waste. Two case studies are presented: a) a cantilever of simple layout used to explain the details of the design methodology, and b) a train station roof structure of complex layout made from elements reused from disassembled electric pylons. For these case studies, Life Cycle Assessment confirms that an up to 63% environmental impact reduction is possible when comparing structures obtained with the proposed method against weight-optimized solutions made of new elements.

This paper presents numerical and experimental studies on semi-active seismic response control of structures equipped with variable stiffness and damping structural joints. Such adaptive joints, which are comprised of a shape memory polymer (SMP) core reinforced by an SMP-aramid composite skin, function as load-transfer components as well as semi-active control devices. The SMP core material can transition from a glassy to a rubbery state through thermal actuation resulting in a shift of the structural natural frequencies and a parallel increase of damping ratio, which enables a new semi-active control strategy. Control performance has been evaluated on a three-story frame equipped with 12 adaptive joints and subjected to seismic excitations. Full-transient analysis has shown that when the joints are thermally actuated to the transition temperature (65 degrees C), acceleration and base shear are reduced by up to 62% and 65%, respectively. Shake-table tests have been carried out on a 1/10-scale prototype, confirming that through thermal actuation of the adaptive joints the structural damping ratio increases from 2.6% to 11.3% and the first natural frequency shifts by up to 37%. As the structure becomes more flexible, an increase of displacements and interstory drift might occur. However, depending on the seismic excitation, top-story acceleration and base shear are significantly reduced in the range 43%-50% and 35%-51%, respectively. These results confirm that semi-active control through thermal actuation of variable stiffness and damping structural joints is effective to mitigate the structure response under seismic excitation.

Adaptive structures can modify their geometry and internal forces through sensing and mechanical actuation in order to maintain optimal performance under changing actions. Previous work has shown that well-conceived adaptive design strategies achieve substantial whole-life energy savings compared with traditional passive designs. The whole-life energy comprises an embodied part in the material and an operational part for structural adaptation. Structural adaptation through controlled large shape changes allows a significant stress redistribution so that the design is not governed by extreme loads with long return periods. This way, material utilization is maximized, and thus embodied energy is reduced. This paper presents a new design process for adaptive structures based on geometry and member sizing optimization in combination with actuator placement optimization. This method consists of two parts: (1)geometry and sizing optimization through sequential quadratic programming is carried out to obtain shapes that are optimal for each load case; and (2)a formulation based on stochastic search and the nonlinear force method (NFM) is employed to obtain an optimal actuator layout and commands to control the structure into the target shapes obtained from Part 1. A case study of a planar statically indeterminate truss is presented. Numerical results show that 17% and 37% embodied energy savings are achieved with respect to an identical active structure designed to adapt through small shape changes and to a weight-optimized passive structure, respectively. The combinatorial task of optimal actuator placement is carried out efficiently. The method formulated in this work produces actuator layouts that enable accurate geometric nonlinear shape control under quasi-static loading through a low number of actuators compared to the number of members of the structure.

This paper introduces a new semi-active strategy for vibration control of truss and frame structures equipped with variable stiffness and damping joints which consist of a shape memory polymer (SMP) core reinforced by an SMP-aramid composite skin. When the joints are actuated to the transition temperature through thermal actuation, the SMP core transitions from a glassy to a rubbery state through a viscoelastic region, which causes a stiffness reduction and an increase of damping. The mechanic behavior of the joint can be thought of as transitioning from a moment to a pin connection. This way, it is possible to cause a shift of the structure natural frequencies and to increase damping, which is employed to obtain a significant reduction of the dynamic response. This paper comprises two parts: (1) characterization of a variable stiffness and damping material model through experimental testing; (2) numerical simulations of a truss bridge and a four-story frame, which are equipped with variable stiffness and damping joints. The truss bridge (case A) is subjected to a resonance and a moving load while the four-story frame (case B) is subjected to El Centro earthquake loading. For case A under resonance loading, the dynamic response can be reduced exclusively through a frequency shift and ignoring viscoelastic effects. For case A under moving load and case B under earthquake loading, vibration suppression is mostly caused by the increase of damping due to viscoelastic effects. Control time delays due to joint heating have been included in the analysis. When the joints are actuated to the transition range 55°C–65°C, which is specific to the SMP adopted in this study, the acceleration peak amplitude reduces by up to 95% and 87%, for case A and case B, respectively. For both cases, damping increases by up to 2.2% from undamped conditions (25°C). This work has shown that the adoption of variable stiffness and damping structural joints has great potential to enable a new and effective semi-active control strategy to significantly reduce the structure response under a wide range of dynamic loading conditions.

This paper presents optimization methods to design frame structures from a stock of existing elements. These methods are relevant when reusing structural elements over multiple service lives. Reuse has the potential to reduce the environmental impact of building structures because it avoids sourcing new material, it reduces waste and it requires little energy. When reusing elements, cross-section and length availability have a major influence on the structural design. In previous own work, design of truss structures from a stock of elements was formulated as a mixed-integer linear programming (MILP) problem. It was shown that this method produces solutions which are global optima in terms of stock utilization. This work extends previous formulations to stock-constrained optimization of frame structures subject to ultimate and serviceability limit states hence expanding the range of structural typologies that can be designed through reuse. Fundamental to this method is the globally optimal assignment of available stock elements to member positions in the frame structure. Two scenarios are considered: (A) the use of individual stock elements for each member of the frame, and (B) a cutting stock approach, where multiple members of the frame are cut from a single stock element. Numerical case studies are presented to show the applicability of the proposed method to practical designs. To carry out the case studies, a stock of elements was inventoried from shop drawings of deconstructed buildings. Results show that through reusing structural elements a significant reduction of embodied greenhouse gas emissions could be achieved compared to optimized structures made of new elements.

This paper presents the formulation of a new methodology to design adaptive structures. This design method synthesises structural configurations that are optimum hybrids between a passive and an active structure. An optimisation scheme searches for an optimal material distribution and actuation layout to minimise the structure whole-life energy which consists of an embodied part in the material and an operational part for structural adaptation. Instead of using more material to cope with the effect of loads, here, strategically located active elements redirect the internal load path to homogenise the stresses and change the shape of the structure to keep deflections within required limits. To ensure the embodied energy saved this way is not used up to by actuation, the adaptive solution is designed to cope with ordinary loading events using only passive load-bearing capacity whilst relying on active control to deal with larger events that have a smaller probability of occurrence. The design methodology has been implemented for statically determinate and indeterminate reticular structures. However, the formulation is general and could be implemented to other structural types. Numerical simulations on a truss system case study confirm that substantial savings up to 50% of the whole-life energy can be achieved by the adaptive solution compared to a passive solution designed using state of the art optimisation methods.

Reusing structural components for multiple service cycles has potential to lower building structures environmental impact because it reduces material resource use, energy consumption, and waste production. One strategy to reuse structural components is to design structures that can be assembled, taken apart, and reassembled in new configurations. This paper presents a new computational workflow to design a bespoke kit of parts that can be employed to build structures of diverse typologies and that are not restricted to repetitive modular arrangements. Key to this method is the optimization of structural members and joints (i.e. the kit of parts) that fit multiple geometries and different structural requirements. The proposed method includes form finding and digital fabrication and it applies to the design of trusses, gridshells, and space frames. This method has been successfully applied to build three pavilion-scale prototypes from only half the number of parts compared to one-off construction.

An important share of building environmental impacts is embodied in load-bearing structures because of their large material mass and energy-intensive fabrication process. To reduce substantially material consumption and waste caused by the construction industry, structures can be designed and built with reused elements. Structural element reuse involves: element sourcing and deconstruction, reconditioning and transport. As these processes also generate environmental impacts, reuse might not always be preferred over new construction. This paper presents a method to design reticular structures with minimal environmental impact made from reused and new elements. The formulation given in this paper is based on a combination of Life Cycle Assessment (LCA) and discrete structural optimization. The LCA carried out in this work accounts for impacts generated from sourcing reclaimed elements to the assembly of the structure. Structural optimization is subject to stress constraints on element capacity and deflection limits for serviceability. Typical loading scenarios are considered. The method is applied to the design of three single-span steel trusses of different topology subject to 100 simulated stocks of reusable elements that have varying cross-sections and lengths. Benchmarks against minimum-weight solutions made solely from recycled steel show that this method produces structures with up to 56% lower environmental impact. Depending on stock availability, the lowest environmental impact is achieved through a combination of reused and new elements.

Adaptive structures are sensed and actuated to modify internal forces and shape to maintain optimal performance in response to loads. The use of large shape changes as a structural adaptation strategy to counteract the effect of loads has been investigated previously. When large shape changes are employed, structures are designed to change shape as the load changes thus giving the opportunity to homogenize stresses. In this way, the design is not governed by peak loads that occur very rarely. Simulations have shown a significant amount of embodied energy can be reduced with respect to optimized active structures limited to small shape changes and with respect to passive structures. However, in these previous studies, the actuator layout was assigned a-priori.

This chapter presents an overview of an original methodology to design optimum adaptive structures with minimum whole-life energy. Structural adaptation is here understood as a simultaneous change of the shape and internal load-path (i.e. internal forces). The whole-life energy of the structure comprises an embodied part in the material and an operational part for structural adaptation. Instead of using more material to cope with the effect of rare but strong loading events, a strategically integrated actuation system redirects the internal load path to homogenise the stresses and to keep deflections within limits by changing the shape of the structure. This method has been used to design planar and spatial reticular structures of complex layout. Simulations show that the adaptive solution can save significant amount of the whole-life energy compared to weight-optimised passive structures. A tower supported by an exo-skeleton structural system is taken as a case study showing the potential for application of this design method to architectural buildings featuring high slenderness (e.g. long span and high-rise structures). The methodology has been successfully tested on a prototype adaptive structure whose main features are described in this chapter. Experimental tests confirmed the feasibility of the design process when applied to a real structure and that up to 70% of the whole-life energy can be saved compared to equivalent passive structures.

Real-time physics simulation has been extensively used in computer games, but its potential has yet to be fully realized in design and education. We present an interactive 3D physics engine with a wide variety of applications. In common with traditional FEM, the use of a local element stiffness matrix is retained. However, unlike typical non-linear FEM routines elements forces, moments and inertia are appropriately lumped at nodes following the dynamic relaxation method. A semi-implicit time integration scheme updates linear and angular momentum, and subsequently the local coordinate frames of the nodes. A co-rotational approach is used to compute the resultant field of displacements in global coordinates including the effect of large deformations. The results obtained compare well against established commercial software. We demonstrate that the method presented allows the making of interactive structural models that can be used in teaching to develop an intuitive understanding of structural behaviour. We also show that the same interactive physics framework allows real-time optimization that can be used for geometric and structural design applications.

The topology optimization problem in its basic form is a discrete programming problem. Binary material variables, x(s) ∈ [0, 1], describe if material is present or void at spatial position s in the design domain. To implement efficient continuous non-linear programming algorithms the binary requirements on the material variables are relaxed. Variables at intermediate values are then penalised to encourage purely binary or ‘black-white’ designs with the ‘simple isotropic material with penalization’ (SIMP) approach. Suggested amongst others by Bendsoe (1989).The general topology optimization problem with local stress constraints is stated as (Duysinx & Bendsoe 1998)where x ∈Rn, q and x ∈Ru. The objective function f0 : Rn+u →R and constraints fj : Rn+u →R, j = 1, 2, . . ., m. Respectively, m and n are the number of constraints and the number of finite elements in the mesh. The vector q denotes the vector of nodal displacements and w the vector of nodal forces (assumed to be design independent), the dimension of which, u, depend on the method of discretization. The elemental stiffness matrix, K , is derived according to the finite element method with SIMP penalization.

The design methodology described in this paper takes a substantial shift from conventional methods. Traditionally sizing is based on the worst expected load scenario. By contrast to this conventional passive approach the method presented here replaces passive member strategically with active elements (actuators) which are only activated when the loads reach a certain threshold. The structure can withstand low level of loads passively. Above the threshold, actuation comes in to allow the structure to cope with high but rare loading scenarios. Active control introduces operational energy consumption in addition to the energy embodied in a passive design. In this paper we use this dual design to minimize the overall energy required by the structures. This methodology has been used on a simple truss structure and it was showed that it allows significant weight saving compared to conventional passive design. We extend the application of the methodology to a more complex 3D structure. It is confirmed that an optimum activation threshold exists that leads to design that minimises the total energy of the structure. Compared to an optimised passive design we show that the total energy saving is 10-fold.

The design methodology explained in this paper takes a substantial shift from conventional methods where sizing is based on a single load case i.e. the maximum expected load. The difference from a conventional passive approach is that strategically located elements of the system provide controlled output energy (actuators) in order to manipulate actively the internal flow of forces and stresses. In this way stresses can be homogenized and deflections kept within desired limits. The alternative we are proposing offer a way to actively counteract loads when needed. Two dimensional pin-jointed trusses designed using this methodology show that substantial weight savings can be achieved respect to optimised "passive" structures (designed using Fully Utilised Design method).While the decrease in mass through actuation leads to reduction of embodied energy, it increases the operating energy that the active elements need to provide. Whole life energy analysis, implemented as coupled optimization between embodied and operating energy, reveals that an optimal trade-off exists. Results show that energy savings remain significant even considering the operating energy of the actuators for the entire life-cycle of the structure.

People with HIV/AIDS (PWHA) have increased risk of some cancers. The introduction of highly active antiretroviral therapies (HAART) has improved their life expectancy, exposing them to the combined consequences of aging and of a prolonged exposure to cancer risk factors. The aim of this study was to estimate incidence rates (IR) in PWHA in Italy, before and after the introduction of HAART, after adjusting for sex and age through direct standardization. An anonymous record linkage between Italian AIDS Registry (21,951 cases) and Cancer Registries (17.3 million, 30% of Italian population) was performed. In PWHA, crude IR, sex- and age-standardized IR and age-specific IR were estimated. The standardized IR for Kaposi sarcoma and non-Hodgkin lymphoma greatly declined in the HAART period. Although the crude IR for all non-AIDS-defining cancers increased in the HAART period, standardized IR did not significantly differ in the 2 periods (352 and 379/100,000, respectively). Increases were seen only for cancer of the liver (IR ratio = 4.6, 95% CI: 1.3-17.0) and lung (IR ratio = 1.8, 95% CI: 1.0-3.2). Age-specific IRs for liver and lung cancers, however, largely overlapped in the 2 periods pointing to the strong influence of the shift in the age distribution of PWHA on the observed upward trends. In conclusion, standardized IRs for non-AIDS-defining cancers have not risen in the HAART period, even if crude IRs of these cancers increased. This scenario calls, however, for the intensification of cancer-prevention strategies, notably smoking cessation and screening programs, in middle-aged HIV-patients.

This work proposes a new direction in structural design: the synthesis of structures through the reuse of elements. Reusing structural elements reduces the environmental impacts of building structures because it avoids sourcing new material, it reduces waste and it requires little energy. Designing structures from reused elements is unlike conventional structural design because stock element availability is a design input. In other words, structures must be designed to fit given element characteristics, e.g. cross-sections and lengths. Stock constraints such as number of elements and element lengths, have a major influence on the optimal structure layout and form. In this new paradigm structural form follows availability. This work formulates new computational methods for the synthesis of reticular structures through reuse. Two scenarios are presented: a) reuse of reclaimed elements from a given stock, and b) design of a common stock which is used as a kit-of-parts to build diverse structures. Case studies are presented to demonstrate the potential of the proposed methods. It is shown that structures produced by these methods have a significantly lower environmental impact than minimum weight structures made of new elements.

This paper presents an experimental validation of a new design method for adaptive structures that counteract the effect of loading through shape morphing. The structure is designed to morph into target shapes that are optimal to take external loads through combined optimization of structural layout and actuator placement. The prototype tested in this study is a simply supported spatial truss that spans 6.6 m with a span-to-depth ratio of 44/1. Shape adaptation is achieved through controlled length changes of 12 linear actuators that are strategically integrated into structural elements. A new mechanics-based framework has been formulated to enable real-time control. Linear-sequential shape optimization is employed to predict target shapes under loading. Actuator commands are computed through an iterative process that accounts for geometric nonlinearity. This formulation allows a reduction of computation time by four orders of magnitude compared with a nonlinear programming formulation. Experimental testing has shown that significant stress homogenization is achieved through shape adaptation, which results in up to 45% savings of material mass compared with a weight-optimized passive structure. Depending on the energy source employed for adaptation, the equivalent carbon is reduced by up to 29% and 43% in the case of non-renewable and 100% renewable energy mix, respectively.

Reuse reduces raw material use, waste generation and energy consumption caused by building construction. A substantial share of these impacts is contributed by load-bearing systems be-cause of their mass- and energy-intensive production process. Therefore, reusing structural components over multiple service lives has the potential to improve the sustainability of building structures. However, reusing structural elements entails reversing the conventional structural design process: the mechanical and geometric properties of available elements predetermine the geometry and topology of a structure. This paper presents structural optimization techniques: 1) for the design of multiple spatial structures from one stock of elements, and 2) for the synthesis of an optimal stock or kit-of-parts whose elements can be used in multiple structures. The objective of case 1) is to avoid the cutting of stock elements, i.e. to reduce waste. In case 2), the objective is to reuse stock elements in as many structures as possible. In both cases, the assignment of stock elements to the structure is obtained via combinatorial optimization. In addition, geometry optimization is employed to best-fit the structure geometry to the lengths of assigned stock elements. The potential of the proposed methods for large-scale applications is demonstrated via case studies of three spatial structures of complex layout: a dome, two three-chord trusses and a tower.

Discrete sizing and topology optimization of truss structures subject to stress and displacement constraints has been formulated as a Mixed-Integer Linear Programming (MILP) problem. The computation time to solve a MILP problem to global optimality via a branch-and-cut solver highly depends on the problem size, the choice of design variables, and the quality of optimization constraint formulations. This paper presents a new formulation for discrete sizing and topology optimization of truss structures, which is benchmarked against two well-known existing formulations. Benchmarking is carried out through case studies to evaluate the influence of the number of structural members, candidate cross sections, load cases, and design constraints (e.g., stress and displacement limits) on computational performance. Results show that one of the existing formulations performs significantly worse than all other formulations. In most cases, the new formulation proposed in this work performs best to obtain near-optimal solutions and verify global optimality in the shortest computation time.

This paper gives a proof of equivalence between two existing force methods (FM) for structural analysis: The Integrated Force Method (IFM) and a force method based on singular value decomposition (SVD) of the equilibrium conditions here named as SVD-FM. Recently, these methods have been employed to design and control active structures. Actuation is employed to counteract the effect of external loading by modifying internal forces and the external geometry in order to meet strength and serviceability requirements. Both IFM and SVD-FM offer an effective way to estimate the combined effect of external loading and that of actuation. Generally, the SVD-FM has a lower degree of computational complexity with respect to the IFM, the more so as the structure static indeterminacy increases. However, the IFM has a more intuitive formulation that is preferable pedagogically and it is of value for future extensions to kinematically indeterminate configurations and to geometric non-linear cases.

Aims and background In Campania two cancer registries have been operating since 1996, covering part of the province of Naples and the province of Salerno, and amounting to 29% of the regional population. The aim of this paper is to provide estimates of the incidence, mortality and prevalence of seven major cancers for the entire Campania region. Methods The estimates were obtained by applying the MIAMOD method, a statistical back-calculation approach to derive incidence and prevalence figures starting from mortality and relative survival data. Survival was modeled on the basis of published data from the Italian cancer registries. Results In 2012 the most frequent cancers were colorectal, breast and lung cancer with 3,969, 3,675 and 3,629 new diagnosed cases, respectively. The cancers with increasing incidence trends were breast cancer, lung cancer and skin melanoma in women, and colorectal cancer and skin melanoma in men. By contrast, the incidence rates of uterine cervix cancer and stomach cancer were decreasing. In men the lung and prostate cancer incidence rates increased, reaching a peak in different periods, and then decreased and stabilized, respectively. Prevalence was increasing for all considered cancers with the exception of cervical cancer. The highest values in 2012 were estimated for breast and colorectal cancer (34,000 and 22,000 prevalent cases, respectively). In the final period under study there was a decline in mortality for all cancers except female lung cancer. The highest crude mortality rates in 2012 were estimated for lung cancer in men and breast cancer in women: 80 and 31 per 100,000, respectively. Conclusion This paper provides a description of the burden of the major cancers in Campania until 2015. The estimates highlight the need to reinforce organized screening, especially for breast and colorectal cancer, and to support evidence-based prevention campaigns against female smoking. All these aspects require continuous and updated monitoring of the main epidemiological indicators in the Campania population.

Adaptive joints are structural joints made of materials with enhanced transduction properties that can vary their stiffness via solid-state actuation (e.g. thermal, mechanical). In this work, stiffness tuning is used to switch the joint between a ‘locked’ (e.g. a moment connection) and a ‘released’ (e.g. pin) state. Previous work has looked into the feasibility of using variable stiffness joints during shape and force control in order to reduce actuation work. This paper focuses on control of the structure dynamic response to loading. The natural frequency of the structure is tuned to escape dangerous resonance conditions in two ways: 1) a geometric reconfiguration via large shape changes or 2) via the change of stiffness of the joints. Two case studies are considered: 1) an active frame integrated with four actuators fitted on tubular elements which are connected by a shape memory polymer joint 2) a planar truss structure. Experimental tests on the active frame have shown that by varying the length of the linear actuators, large shape changes can be employed to effectively change the natural frequency of the structure. During shape change, the joint stiffness is lowered to ease geometric reconfiguration. For the planar truss case study, simulations have shown that the ‘release’ or ‘locking’ of multiple joints can be employed to change the eigenfrequencies, the more so the higher the eigenmode.