Structural analysis of greenhouses: A case study in Turkey

ANADOLU JOURNAL OF AGRICULTURAL SCIENCES, 2013

The safe design of greenhouses is of great importance and requires special attention. Computeraided design and information technologies allow faster, easier and more reliable designs. Such designs were taking long hours when performed with classical methods by hand. Today, there are numerous computer softwares being able to perform calculations and dimensioning of greenhouse systems reliably and practically. This study was mainly focused on analysis and design of greenhouses by using SAP2000 computer software to achieve more accurate results in less time by incorporating computer use into the process. A sample greenhouse design was performed and analyzed by using SAP2000 software, and the findings regarding safe design and analysis were reported.

The Andhra Agriculture Journal, 2018

Design loads of greenhouse include dead load, crop load, snow load, wind load and live load. The structural design of greenhouse must withstand from extreme combination of all types of load. In this paper, an attempt has been made to analyse the various loads of greenhouse. In India, the basic wind speed varies from 33 to 55 m/s. Along with wind speed, wind load also depend on the geometry, height to width ratio, effective frontal area etc. So greenhouse design should be customized as per the localized wind load. Among all the loads that act on the greenhouse, wind load is the major one (772 N/m 2). In this experiment, wind load for the saw-toothtype naturally ventilated greenhouse was estimated as per IS code 875 (part 3)and IS 14462: 1997. The design wind pressure estimated to be 772 N/m 2. The live load, crop load, truss load and load due to frame found to be 250,200, 250, 100 N/m 2 respectively.

Agriculture

Commercial production greenhouses are widely used to produce plants and crops. From the structural engineering viewpoint, among the loads that act on greenhouses, wind and snow loads are the major ones. This paper focuses on the former, particularly on wind pressure coefficients. Design and construction of greenhouses should consider wind loads in order to ensure seamless operation, overall stability, durability, and safety, even though human occupancy is limited. Classification and design of greenhouses is typically based on European standards, which cover a variety of geometries and conditions. Some recent research studies suggest, however, that greenhouse design standards should be revised to ensure structural safety of greenhouses subject to strong wind loads. Triggered by this recent outcomes, this paper reviews existing literature on the topic: (a) briefly presenting the state of the art methods for determining wind pressures on greenhouses; (b) comparing the EN 13031-1 pressu...

Agriculture

A composite plastic material made of recycled Polyethylene terephthalate (PET), Nylon, and glass fiber reinforced Nylon was innovated and applied to the construction of a prototype simple greenhouse in this study. With reference to the mechanical properties of a conventional galvanized steel greenhouse, sectional dimensions of the composite plastic structural members were determined. Structural performances of the conventional galvanized steel and the composite plastic greenhouse models were analyzed under static design wind loads. It was realized that the greenhouse model designed with composite plastic 田-sections of 5 mm wall thickness could have peak displacement response and sectional forces comparable to that of the galvanized steel greenhouse. Therefore, the 田-sections with 5 mm wall thickness were manufactured and used to construct the prototype simple greenhouse. On-site free vibration tests were conducted to estimate the dynamic characteristics of the prototype for validati...

2019

Sera, bitki uretimi icin gerekli buyume faktorlerini saglayan ve bitki yetistiriciligi icin mekanizasyon imkanlarini kolaylastiran tarimsal yapidir. Sera tarimi, tarimin en onemli gelir getirici kollarindan birisidir. Gunumuzde, bilgisayar yazilimlari seralari planlarken de kullanilmaktadir bu sekilde daha saglam ve ekonomik bir yapi elde edilebilmektedir. Isletme sahipleri, seralara sermaye yatirimi yaparlarken, mevcut seralarin yapisal ozelliklerini tum yanlis hesaplamalarla ve hatalarla birlikte kopyalayip yeni projelere aktarmaktadirlar. Tum yatirimlar ve yatirimlarin gelecegi yanlis hesaplamalarla ve yapisal sorunlu projelerle tehlikeye atilmaktadir. Sonuc olarak, statik ve mukavemet hesaplamalari yapilmadan insa edilen seralar, daha fazla malzeme kullanilmasi, yapisal hasarlar ve bunlara bagli olarak meydana gelen ekonomik kayiplarla yuz yuzedir. Bu calisma, Antalya ilinde bulunan 720 m 2 alana sahip tek aciklikli cam kapli ucgen catili bir seranin yapisal analizlerini icermek...

2022

This is the second volume of a four-volume work on passive solar greenhouses. This particular volume deals with the design of greenhouse frames using timber, presenting both mainstream and experimental techniques. In doing so, it addresses both agricultural greenhouses and greenhouses or sunspaces intended to serve architectural purposes, including the ones that may be typical of urban agriculture, and both self-standing greenhouses and attached ones. The topics range from connections of timber components to light-frame techniques, timber frame techniques, truss-frame techniques, foundations, and wind-bracing. The entire treatment has an emphasis on facilitated techniques suitable for self-construction. In the final part of the volume, the topic of auxiliary heating and cooling systems is addressed, which has strong links to the subjects covered in the other three volumes.

Jarq-japan Agricultural Research Quarterly, 2000

Natural ventilation system modifications were evaluated using a computational fluid dynamics (CFD) numerical model (code: Fluent Version 4.5). Wind speed and direction, side vent opening size and location, roof vent opening type, and number of spans were examined in terms of ventilation rates and airflow distribution. For the side vent located at 2.5 m above the floor with a west wind of 2.5 m/s, 59% of the incoming air through the side vent was predicted to move out through the first roof vent opening without reaching distant areas in the greenhouse, resulting in high inside air temperatures. The air mainly moved in through the side vent and fourth roof vent openings for an cast wind of 0.5 m/s while the third and fourth roof openings were the only predicted inlets of airflow for an east wind of 2.5 m/s. The hinged open roof multi-span greenhouses were predicted to have significantly higher natural ventilation rates than the double polyethylene-covered multi-span greenhouses for al...

2022

This is the fourth volume of a four-volume work on passive solar greenhouses, presenting both consolidated and experimental techniques. This particular volume focuses on strategies for preliminarily calculating the thermal performance of greenhouses, simulating it with transient environmental performance simulation programs, sizing structural elements through both explicit simplified calculations and advanced structural simulation programs, and exploring design options automatically using optimization programs and surrogate modeling techniques. The second part of the volume presents real-life examples, many drawn from the field of architecture, analyzing both their environmental and constructional choices.

E3S Web of Conferences

The aims objective of this work consists to study the storage system effects on the thermal performance of a tunnel agricultural greenhouse. The study focus on the use of the data climate analysis to predict the outside needs as comparison with another without storage system. The obtained results indicate that the outside needs are less than the no heated with 3 to 5°c during winter night. The thermal behavior of the greenhouse was study numerically and the results are corroborating with the literature. In addition, we conducted a comparative study designed to identify the optimal form of the greenhouse; two geometrical configuration are considered.

revagrois.ro

Greenhouse construction has been involved in various fields. Besides agronomy, forestry science and technology and horticulture in the traditional sense, the architecture, aesthetics, mechanics, steel structure, ergonomics, computer automatic control, air conditioning and new materials. etc. are increasingly involved as well. Technology has been adhering to such principle and introducing talents in various fields to make greenhouse widely applied to each field without being exclusive to agriculture and forestry. The advantages offered by protected horticultural culture can be capitalized in a superior way, in achievement conditions of horticultural micro-farms in framework of some agricultural educational institutions. Analysing existent conditions at Agricultural Scholar Group Al. Vlahuta from Sendriceni-Botosani, was elaborated technical-constructive solutions for greenhouses project on 0.50 ha surface. Planting materials achieved in some protected spaces will be planting in land, on a 4.00 ha surface. About spaces for specific production activities was foresee an educational pavilion, with a classroom and afferent utility, for a good unfolding of didactic process.

2011

The objective of this paper is to analyze the shape and cross-section of bamboo structure for a single greenhouse in Thailand. The green house is designed to open on the roof for ventilation, and under geometrical constrains for minimize deflection. We calculate the cross-section, self weight and displacement values of bamboo structure to determine the truss shape design problem in the greenhouse. The truss shape has designed in eight different types: Double Howe, Modified Fan, Modified Queen, Pratt, Fan, Double W, M shape and W shape. The displacement value in each truss shape is determined by using standard load (Dead Load, Live Load, and Wind Load) to calculate axial force in each truss shape member. The results of eight type displacement values show that the minimum displacement is Modified Fan truss shape and the minimum weight of the trusses structure in greenhouse is Double Howe truss shape.

Journal of Cleaner Production, 2022

Today, advancements in greenhouse technology and modifications have pushed science-based solutions for optimal plant production in all seasons worldwide by adjusting internal climate growing factors such as temperature, humidity, light intensity, and CO2 concentration. Solar greenhouses increase crop yield and quality, addressing global food security concerns. This paper presents an overview of current design trends in construction, current development technology for controlling and monitoring greenhouse microclimates, and the various systems available for managing greenhouse environments. First, it discusses different processes of the greenhouse geometry, orientation, and cladding material for different climates. This paper also examines the various strategies in the greenhouse control environment, sensing networks, different wireless gateway used in monitoring systems, and the many control approaches. The last section of this review presented the system for managing climate in the greenhouse. The results of this research are the best selection of geometry, orientation, and covering material of the greenhouse also achieves a suitable environment, as well as the strategy of control and management of climate, plays a vital role in achieving high crop production and decreasing the cost and the energy consumption.

International Journal of Production Economics, 2011

This paper offers mutual exchange of knowledge and expertise between agriculture and productioneconomy by economical evaluation of greenhouses. Greenhouses are Hi-Tech horticulture farms, in which advanced technological infrastructure increase production efficiency by providing optimal growing conditions. However, this infrastructure involves high capital investments. There are other cost sources, of which labor is dominant, generally in horticulture and in greenhouses in particular. Efficient use of space and labor are often conflicting goals in greenhouse layout design. In this paper, these conflicts are presented and illustrated, and tools are developed to evaluate layout design by the resultant annual operational profit, thus enable comparison of alternative layouts. To increase accessibility, spreadsheet software is used for the calculations. Further, the spreadsheet is designed to support WHAT-IF analyses. The applicability of the proposed approach is demonstrated via numerical analyses of layout design of an actual greenhouse for pepper growing using the Holland method. Evidently, the layout design can have significant effect on the economical efficiency of the greenhouse-annual profit increases by, at least 12%, and up to 40%! The tradeoff between space utilization and resource utilization; e.g., labor, is common to all greenhouses, whether vegetables, flowers or other plants are grown in them and the tools presented herein can be easily modified to any desired case.

Acta Horticulturae, 2017

Urban horticulture has intensified in recent years. The trend has resulted from a growing interest in the development of new agricultural spaces in urban areas. In this regard, the Integrated Roof Top Greenhouse concept (I-RTG) is based on the construction of RTGs with interchange of residual energy (heating/cooling), water and CO 2 fluxes between the greenhouse and the associated building. With such greenhouse system, potential benefits from environmental, economic and social points of view can be achieved. In 2014, a research-oriented roof top greenhouse was constructed on top of the building that hosts the Institute of Environmental Science and Technology (ICTA Universitat Autonoma of Barcelona, Spain). It is called the RTG-Lab. Floor surface is 122.8 m 2. It is a two-span, sloped-roof metal structure covered with single-layer polycarbonate sheets. The first crop (lettuce) was planted in perlite bags on September 2014. Currently a tomato crop is growing in the greenhouse. This article presents the first evaluation of the RTG Lab in terms of climate performance. In contrast with conventional greenhouses, thermal inertia of construction elements in the RTG Lab (viz. the concrete floor) made a significant contribution to the night-time greenhouse temperature. The RTG Lab also benefited from the air exchange with the associated building, particularly at night. Additionally some waste heat from the building climate equipment made it possible keeping the greenhouse temperature at favourable conditions without using any additional heating. Some peculiarities of the RTG Lab, such as the different wind regime in comparison with conventional greenhouses are also discussed.

2022

This is the first volume of a four-volume work on passive solar greenhouses. This particular volume deals with the preliminary design choices for defining the shape of a passive solar greenhouse and presents both mainstream techniques and experimental ones. The design choices involve selecting the solutions for the construction of its envelope, back wall, gable walls and ground treatment, positioning the thermal masses, sizing and placing the ventilation openings, as well as choosing and positioning the shading devices and thermal shades. The treatment addresses both agricultural greenhouses and greenhouses or sunspaces intended to serve architectural purposes, such as those that may be encountered in urban agriculture, and deals both with self-standing greenhouses and attached ones. The concepts are richly illustrated, and the topics build up incrementally, beginning with the historical trajectory of greenhouses and progressing to criteria for achieving advantageous solar exposure, wind-driven ventilation, and stack-effect ventilation, as well as advanced strategies for balancing thermal stability with thermal responsiveness through the arrangement of openable enclosures, shading devices, thermal curtains, and reflectors.